New washing machine incorrectly installed by Currys - what can I do?

Long post incoming.

In late December 2017, I purchased a new washing machine online from Currys. I also purchased the installation service as a part of the order so that Currys would not only deliver the machine but also install it.

The machine was delivered a few days later at the end of December 2017. It was unpacked and installed by two members of the Currys delivery team. Once the machine was hooked up, the team turned on the machine and put it on its quick wash cycle and told me to leave it running while they took away the old faulty machine (which I had also recently purchased from Currys) back to their van. While they were away, I noticed that the machine was rocking back forth when I physically moved it. It was clear that the machine needed to have its feet adjusted to make it stable. The main installer then returned on his own (his colleague remained in the van), and I said him that the machine was not level and demonstrated this by rocking the machine back and forth.
He had what looked like a pliers in his hand, and he said he would fix it. As he got down on to the floor to adjust the front legs of machine, I told him that the machine is supposed to come with its own levelling spanner, which is specfically shaped to fit around the levelling nuts and lock bolts on the feet. He responded by telling me that I've asked him to level the machine, so I should just let him get on with it.

He then asked me to hold the machine up while he made adjustments to the front legs (at no point did he attempt to adjust the rear legs). I held the machine up wondering why on earth I was asked to do such a thing while his colleague remained in the van. After he made the adjustments, I checked the machine's stability and still felt movement suggesting that it wasn't levelled properly.
I pointed this out to the installer and noticed he seemed annoyed. He responded by telling me that my floor wasn't level and that if I want to adjust the machine a specific way I should do it myself. He then swiftly left, clearly bothered by the fact I simply asked him to level the machine correctly. Attempting to process the awful customer service I had just received, I forgot to request the supplied levelling spanner that was part of my washing machine package.

Later while clearing up, I realised that the delivery team not only took my machine's levelling spanner, but also decided to take brand new cold inlet hose that was supplied with machine. (The installer told me that it was ok to install the machine with the existing hose to which I agreed). During the installation, he left the new hose on my worktop, but after he left I realised it was gone. They had both items with them.
I phoned Currys later that evening and explained how the team had taken parts that were my property. They contacted the manufacturer to order replacements. I was told by Currys that the manufacturer begrudgingly agreed to replace it. I have supplied the information requested by the manufacturer and am still - to this day - waiting to find out if they will actually replace the parts that were taken.

Anyway, a couple of days later I decided to try the washing machine for the first time with my usual laundry load . Things seemed to be going fine until the machine reached its rinse cycles (where the drum speeds up) and violently began vibrating. The vibration when the machine entered its final spin was so intense that the appliance began to come out from the space where it is installed.
It was clear the machine had not been levelled correctly. I noticed that I could, again, physically rock the machine back and forth. So I contacted Currys again, explained the symptoms and requested that I'd like an engineer to take a look and correct the problem. A few days later, a couple of engineers turned up with tools. I described the symptoms and told them about my experience with the delivery team.

They told me it would be a two minute fix.They apologised and told me that Currys' delivery teams often simply unpack machines and never bother to level them after installation, and that it was simply "luck" if customers got a good installation. One engineer pulled the machine out and dropped it causing it to slam into the floor on its face (drum door side). I didn't say anything when that happened.
The second engineer then looked at the feet and instantly established that the feet hadn't been properly adjusted. He made some tweaks to the feet and they righted the machine and put it back into its place. They then tested it by running the Spin programme at the highest rpm (1400) with nothing in the drum. The machine remained stable through out the cycle and they told me that meant the problem was corrected.

I thanked them and they left. The next day, I loaded the machine with my regular laundry load and hit start expecting everything to go fine. Unfortunately, when the machine began the first of its four rinse cycles, the aggressive vibrations returned. The vibrations were so strong that I had to firmly place my hands on the appliance to reduce the loud tapping noise and movement. I had to do this for the further three rinse cycles and final spin just to make the rest of the wash cycle bearable. I videoed the whole thing on my phone so I had proof of just how unbearable the vibrations are.

I contacted Currys again via the Team Know How helpline. I explained how I still had the problem with the machine, and I wanted it corrected. For some reason, the lady on the phone decided it was the manufacturer's problem (and not Currys' incompetency) and forwarded me to the manufacturer's helpline.
Again, I explained everything, they ran through a series of diagnostic tests over the phone and asked me about how it was installed. I said it was installed by Currys inside the kitchen of a second floor flat. The manufacturer's representative on the phone then, rather absurdly, told me that the machine I purchased isn't designed for suspended floors. He then agreed that it was likely a installation issue than an actual defect and handed me back to Currys.

I then explained to Currys that I had just spoken to the manufacturer and they had diagnosed it as an installation issue. I told Currys that I simply wanted a qualified engineer to correctly level the machine. So they arranged for someone to look at it on 7 January 2018.
Last night I found out that my appointment time slot would be early this morning. So I woke up this morning, cleared the area around the washing machine and waited for the engineer to turn up. I got a call from a man speaking poor English who told me he would be up in five minutes to fix the problem.

I looked out of my window and saw a large delivery truck pull up. One man gets out while the other remains inside. I go to greet the man at the door and recognise that is one of men from original delivery team (the one who stayed in the van while the installation happened). He turns up equipped with nothing but a pair of heavy duty gloves. No tools, no spanners, no spirit level - nothing. I explain to him that the machine was not installed correctly and told him that they took my spanner and inlet hose. He didn't seem bothered.
He pulled out the machine, rocked it about and said it was level. I told him it wasn't and showed him my video evidence. But he wasn't interested. He told me it is my floor that not level and proved this by pulling out the machine further and showing me that the machine didn't rock when moved to another part of floor (specifically the middle of my kitchen).

I explained to him that my machine resides under my worktop not in the middle of my kitchen, and that the whole point of machines having adjustable feet is to compensate for uneven floors. He then aggressively pushed the machine back under the worktop, turned it on and started the quick wash programme and pointed out that the machine wasn't shaking. I told him that of course it wasn't shaking, because it was at the start of the programme, ie the drum wouldn't be spinning fast at that point.
He then proceeded to fumble about with various programmes. I told him the machine vibrates when the drum is spinning fast on the spin programme. He responded by telling me that he didn't have time for that. He then pulled the machine out again while it was still taking in water and titled it backwards. I told him to stop because I feared he was going to damage the machine.

I then said to him that I requested an engineer not someone from the delivery team. He again aggressively pushed he machine back under the worktop and said to me that he couldn't level the machine so that it would remain stable under the worktop. I had to tell him several times to leave the machine alone, that I would contact Currys. He then attempted to get me sign some paperwork, which I refused to do on the grounds that the problem hadn't been fixed. He then swiftly left and I shut the door.

So after all that today. I am now left with a brand new washing machine that violently vibrates when it speeds up simply because it hasn't been correctly levelled. I haven't contacted Currys helpline because I haven't got the mental strength be on hold again. Although this post is long, what I haven't mentioned is the hours upon hours that I have spent on hold to the Currys TeamKnowHow helpline. Not just for this washing machine, but the previous faulty machine that this machine replaced (I'm also still waiting to be refunded for the previous machine).

My telephone bill is so high as a result, and I am at breaking point and in the last few months, I have frequently felt suicidal because of the way Currys have handled things. I am normally quite a mentally resilient man, but this experience coupled with the experience I had with the previous machine has absolutely destroyed my mental health. I am on a low income, and I don't know how I am going to pay the telephone bill due in February.
If a washing machine wasn't an essential appliance and the helpline were free, then I'm sure that I wouldn't be so profoundly affected. Knowing that Currys' have managed to extract so much time and money from me makes me as if I am going to go over the edge. All I want is a washing machine that is installed correctly and operates safely. I never experienced any issues with severe vibrations with the washing machines that have been previously installed in the same location, so I believe it can be done. I just don't understand why this so difficult for Currys to achieve.

I can't ring Currys Team Know How helpline again. Mentally, I just can't do it, and financially, I can't afford to. I feel sick when I look at the telephone charges that I have racked up so far as a result of Currys' continued incompetence. I normally don't use my telephone much so only usually rack up about £10 in call charges on top of my quarterly BT line rental. I've racked up almost £100 so far directly as a result of my problems with Currys and most of it has simply been because I have been on hold.

So I'm sitting here typing this in the hope that I can get some advice on how I can resolve this matter. I really don't have anyone else to help me with this. I have the following questions:

1. The machine still vibrates violently when it enters its high-speed spin phases. It's not the kind of vibration that can be tolerated. It's clear Currys haven't corrected the installation despite several attempts. Today, they sent an unequipped delivery team to attempt correct the issue when I specifically requested a engineer. What can I do next?

2. I have wasted so much time (setting aside days and hours spent on the phone) and money (call charges) and suffered a tremendous amount of mental distress as a direct result of the poor installation done by the original delivery team. Can I seek compensation for this?

3. I still haven't - despite receiving email confirmation - received my refund for the previous washing machine that was uplifted and returned to Currys. What can I do about it?

4. Are there any organisations from whom I can seek help from regarding this matter? I feel as though I cannot cope with this on my own. As each day passes, I feel even more powerless and hopeless.

TLDR: New washing machine recently purchased online. Incorrect installation by retailer's delivery team results in violent vibrations during operation. Retailer has failed to resolve the problem despite several attempts.
Significantly inconvenienced and have racked up excessive call charges to helpline as a result of Retailer's incompetence.
Have yet to be refunded by retailer (despite receiving email confirmation of refund) for faulty washing machine that this new machine replaces. What can I do?

Any thoughts and suggestions would be much appreciated.

Thanks.