You appear to be stuck - that is, your mother won't pay the bills herself, and won't go after your father to pay them. If they won't pay, and you don't have a legal basis to enforce the support order yourself (as a nonparty to the divorce), the bills will continue to sit unpaid. Your parents may have a duty to pay the bills if they were incurred while you were a minor, depending upon where you live, but if they don't do so voluntarily even then you would have to sue them. And otherwise, you seem to be left with paying the bills yourself. They're not leaving you with any good options.

