Before I start I fully appreciate this is all my fault, I've got myself into a huge mess and I'm not asking anyone to sympathise but feel like I've just dropped into a pit and could really do with some advice about what to do next.
Don't want to ramble on, so sorry if I drip feed, but basically about 5 years ago I had a problem with tax credits where I sent in the annual renewal but they later said they hadn't received it. I phoned up and thought it was (eventually) sorted. A few months down the line (not sure how long exactly) they sent me a demand for the whole previous years' tax credits, virtually £2.5k, and I rang up again and they said they'd look into it. I heard nothing back so I thought, very stupidly it was sorted. About a year-18 months later I got another demand for the money, and again phoned up but this time they were adamant I couldn't have sent the renewal pack in and would have to pay it. After quite a few phone calls I ended up leaving it and heard nothing again so convinced myself it was ok.
Should say at this point I'm not hugely naive or lazy, I was very depressed for years but have only realised and admitted to it in the last few months. It was far easier just to bury my head in the sand and act as though problems didn't really exist or weren't as bad as they were, so unless I'd actually had a new letter about it I could convince myself it was sorted.
After that I even had someone visit at the door about it but I explained the situation and he said to send in details about when I sent the form etc and they should sort it. Am very ashamed to say I didn't, just buried my head again.
They even stopped my tax credits at some point and I only started claiming again after I moved in with DP, I was almost too scared to claim them before, as if there'd just be more problems.
Now I've just got another letter, from a debt collection agency now, asking for the £2.5k. We haven't even got £250, there's no way I could even begin to pay it back but I'm clinging on for dear life to the possibility maybe I don't have to? It wasn't overpayments, I was entitled to the money, just they didn't receive the renewal form, but is that completely irrelevant after this long? Do I owe all that?
I phoned the debt collection company today who said I'd have to get tax credits to cancel the collection, then tried to phone tax credits but couldn't get through and doubt I will any time soon - it's renewal time after all. I know years ago you used to be able to go to tax credit offices in person - you can't now can you? Would CAB be able to help or would they say I was just stupid and need to figure out how to pay.... which is what I'm expecting right now.
Feel so down and panicky about it, not least because I know it's all my fault for not making sure it was sorted years ago. I'd be really grateful for any advice right now.