The CSA should owe me

What it is I was paying child support for 17years my sons was going to college dropped out quite while ago he’s moved in with his girlfriend they getting nearly 58pounds wk income support.

I had money took off my pay last month t month before that and still come off there trying to say I’m in arrears which they did before I went to solicitors won my case I phoned bk up another lady said it’s deferall come up saying u owe but she said I shouldn’t owe anything they owe me.

My x wife has not informed them my son is getting benifits With girlfriend also they said she has to inform them when child benefit stopped surly they can sort this mess out csa are pain and to other fathers fight yr case don’t let them win.