CSA Arears

JDSB

My ex says she has recieved no money for our 20 yr old daughter but i paid every month some cash but alot in to her bank, i have some reciepts but the CSA say it is not enough evidence, and i am paying £260 a month in arrears £30'000 total over the next ten years, she won't admit i have given it to her as she willl be done for benefit fraud can i take her to court or can i tell the social she had the money, and if i win do the CSA have to give me back the money i have already paid extra?
Also if not can i get the amount i pay per month reduced as i have two other children that live with me aged 5 and 7 thank you.

DUTR

Was there a case open?
If there was, were you paying via the CSA?
If you were paying direct, was this through agreement with the CSA?
Were you not getting an annual schedule which shows what to pay and if there are any arrears or excess.
It doesn't work on he said she said, more on what the 'parents' actually do or did or didn't .