Ex stopped paying the CSA, and the CSA said it is my fault

I set up my child support using the csa in May, this was due to late payments from my ex husband. In August my ex took the girls away on holiday and called the csa to stop my payments. They then stopped the direct debit and i have had not money since. I have tried to resolve the problem with them but they come across as if they are more for him. They have told me he is over £700 in arrears now.

Today the girl i spoke to said i shouldn’t rely on this payment and its my own fault.

How do I get these payments made I’m in the red with my bank.

Many thanks jo.