Virgin Mobile fiasco

Ash860

I took out a sim only £7 per month contract with Virgin through Carphone Warehouse in Aug '14. I get free minutes, texts and 500mb download per month. In November I found that Virgin had been charging for everything and my account had been debited £29 in Sept and £52 in Oct. So in early Nov I called Virgin to inform them of their mistake. They checked it out and agreed that they were wrong and promised to refund me the full amount less the £7pm that I should have been charged (after checking that I had remained within my allowances, which I had). So imagine my surprise to check my bank account this month to find that not only had they not refunded me about £67 as promised but they had charged me another £50 in November!
I called Virgin again on 9 Jan only to be told that they had indeed processed my refund and that I should have received £67. After internal discussion they came back to ask for me to send copies of my bank accounts to prove that I hadn't received the money. I conclude from this that they thought I might be lying. Regardless of this inflammatory request, I scanned copies of my bank statements and emailed them to Virgin. This, they said, would allow them to escalate the matter via our respective banks. They responded (4 days later) to say they tried to speak to me (I did miss a call from them) and if I could contact them again they would like to resolve the issue. I could have contacted them via their website, email or phone. So I phoned. But customer services can't redirect you to The Team (the dept that deal with complaints) so I emailed. By which time I am beginning to feel weary, upset and a little humiliated but I will persevere...
Yesterday I got an email saying that they almost agree (they miss by £2.47) with my calculation of a refund and will process this so that it will be in my account within the next 7 to 10 working days.
So who was telling porky's then? Because back in November they promised to refund me with money being in my account in 7 to 10 working days but that never arrived and on 9 Jan they were promising to escalate this bank to bank on my behalf!
I have told Virgin that I was prepared to accept that an admin error could have been to blame for the initial incorrect charging, but having brought the mistake to their attention, to compound the error is inexcusable and I am left feeling that Virgin have stolen my money. I am £111.70 out of pocket, not to mention the distress and aggravation this has caused me.
Is it normally this difficult to be a mobile customer?