Back child support in New York State?

Alright, my soon to be husband owes back child support, his ex has totally screw us over by lying, saying he owed her over 10,000 and she won because he was just paying her and she agreed to it, not through the courts or child support and he never though she would do this to him. We just got a letter saying they took his state... We though she would only get his federal, to be begin with, as far as federal we have heard nothing. Can anyone clear this up for us? I mean we knew his federal was absolutely going to be taken, we just thought we could get his state.