Can I be forced to repay foodstamps 19 years after the fact?

In 1992 I went through a bad divorce. My husband of 4 years married me and morgaged my house which was paid off at the time, to pay his past bills including his xwifes credit cards. In the divorce from me he refused to make the 450 a month morgage payments, said he would file bankrupsy on it before he would pay. My lawyer set the payments up as alomony so he couldnt file on them. Iwas a college student at the time with 2 minor children by my first husband at home . I had to get foodstamps to feed us when he left taking our only income other than child support. I called my caseworker at the Human Service Dept and told her what the lawyer did and she ask if I was keeping the money and I told her no it went to Beneficial for the morgage payments, so she said it was OK. Then years later they sent me papers that I had to pay back the foodstamps because I failed to report the 450 a month income. I went to the hearing they set up and told my story. My caeworker denied me ever calling her. My Lawyer was sick at the time but sent a statement..Now 19 years later I received a letter today that I owed $3, 700.00 back or they would turn it over to a lawyer.. What can I do?