Consumer rights help

Fender4

Hey all. 
I purchased a sofa bed designed for everyday use in 2016 (I spent the extra money knowing that this was an everyday use one. I wanted to keep this sofa for many years) 
in 2018 one of the springs snapped I was fobbed off saying there was nothing they could do as they no longer stock the sofa. I complained and was told I would need to pay £48 for an independent review but because the sofa was over 12 months old they wouldn't give me a full refund if I returned it. (I can not find any warranty details at the moment but I can confidentially say it should be more than 12 months for a sofa)  
I called for independent advice (a company suggested by them) I was told.. "don't worry I'm surprised the manufacturer didn't help you. ill just send you a spring in the post"  I thought you know what lets see how I get on. 
Fast forward to now and not just the spring has broke but also the wire holding the bed (trampoline type) surface in place. 
I reached out to them again and they told me "If this is deemed to be a manufacturing fault, based on the amount of time you have had the product we would offer a depreciated refund and return of the product. This is in line with the Consumer Rights 2015, or alternatively an option to keep your product with compensation.

So today the independent company came to my house to inspect the sofa which I paid for. Still pending the report but he made it clear that this is indeed a manufacturing fault and should never be like this.
 
Thanks for following so far.... So I need to reach out to them to let them know but I'm just wondering what are my rights. I feel like I'm going to be stuck between a rock and a hard place, If they say something like here is £50 compensation or we will give you £200 if you return it. It's all felt very lets do this independently but now it feels like they can offer whatever they want as I have no clue how to interoperate the consumer act for something like this. 

Any help would be appreciated so I can see expectations and will know what others will think is fair. The last thing I need to be doing now is having to spend more money (even if it was a like for like) for something out of my control. but I guess I have no choice. 

Spank

You should have posted in the consumer rights section.

No idea how much you will be offered as you haven't said how much you paid for it. Look for your sofa on 2nd had sites and see how much they are selling for.