[Solved] False allegations CMS not listening

So my ex has lodged a complaint about missing payments. I pay direct pay to her. One was for christmas 2017, we were actually back together romantically and I had my son all week and she said not to worry about that weeks payment as I'd spent so much...yes she was still claiming through the CMS although we were back together but not living together. The next payment was the 15/06/18, we had split up in march. I looked back at my statements and it was correct, the payment didn't go out. I contacted the CMS and explained about christmas and also said if they deem I still have to pay I know I have too and am completely willing to make those missed payments, I didn't realize the 15/06 one was missing and my ex hadn't notified me. So far so good, they understood and accepted that. Since the 06/07 this year i''ve been on sick pay after a nervous break down. I used their online calculator to figure what I had to pay her, in the past when we were together and I had time off sick she accepted that and I stupidly thought she'd understand now...wrong! So the CMS told me tooopen an online account with them, photo my wage slips and they'll assess it. Their system had lots of problems and they acknowledged that and by the time I got too upload my slips it was one day over the 14 days. Next day I have an order for collect and pay which I objected too on the grounds I'm happy to get this resolved and pay any difference. Yesterday the case worker rang me and good god was he aggressive and angry. I was trying to explain and he just snapped at me "you've missed more than that" I said pardon he went on to say "you've missed more than that so an appeal against collect and pay won't be considered". I started to explain again and he cut me down saying we can talk about this all day and nothing will change and stated "you owe £2219" In shock I said I beg your pardon, that comes too 31 missed payments, "that's right" he said "your ex has claimed you haven't paid anything since christmas 2017. I told him thats' an outright lie and can prove it, and asked for 14 days to supply the evidence, he said I'd had enough time and haven't sent any evidence in and they don't accept photographs!! I had to explain again that I did what I was told and the letter and claim said nothing about an accusation of 31 missed payments, that i've just learnt of this now from him so surely I get 14 days before a decision of collect and pay is made. He said they will look at the statements when they get them, that I can take all the time in the world to send them in but advised to do it quickly, in the mean time the collect and pay is staying!! He kept saying "you haven't paid since christmas", I asked if she had shown evidence of the missed payments he said no, ok I said, so how can you say with absoloute certainty I haven't paid, until I get my bank statements to you this is an accusation not an actual fact and I do not appreciate being made to feel like a criminal when I haven't done anything wrong. Blank. Get the statements to us and we'll review it, I asked what will happen to my ex when they see she is lying, he replied, we'd have a word with her.
So I looked on my online account with them and less than twelve hours after the phone call the cost has now risen too over £3000!!! and still climbing, its like the computer system has gone mad. The new calculation as to what they will take is now more than I earn in total!!! I have no idea what to do, its like I have no control and no say, all she has to do is lie and my life is [censored] again, just like it was when I was with her.