I had my daughter 12 years ago was receiving welfare, who was taking support money from my ex he was tested for paternity when my daughter was 2 and

There is not a lot of information here to give a firm answer. Whether the father is the biological father based upon paternity is one issue that may mean he is off the hook for further child support. However, if he acted as the father and accepted responsibility as the father regardless of whether he was the biological father or not also makes a difference. However, if he insisted on being tested from the beginning and never held himself forth as the father would mean he is no longer going to be required to pay child support. As to what he might have already paid, I think you might want to check with welfare. They would have been the ones receiving the payments.