How do you get off being a default father?

I had been added as the default father because my name is in the system, I never took a paternity test nor have a spoke to the woman, but since she said my name and I already have a child support case. They added me as the default father on this lady case. I cant see or talk to her but they are taking money from me. I called and try to get someone to help me on this. They told there nothing I can do and I will continue to pay and it wont be stopping ever. Please help me with advice because I have paid this for too many years and I know this isn't my child. I'm just getting used because my name is in the system. Thank you in advance for your help