Should I still allow my son's father to see my son if he refuses to pay off child support debt to govt?

I received a call from child support yesterday telling me son's father has not paid off any of his debt back to govt (as I was on welfare) and they are willing to do a settlement with him where they would take off $20,000 of his debt. My son's father is not even willing to compromise on any settlement. He just blames me for all his problems...saying that I caused the govt to take money out of his credit card machines and bank accounts. He refuses to pay them anything and said I had no business collecting aid in the first place.