Surely there must be an attorney in town who deals with dead beat father issues? If I were you, I would persist until you found one willing to help. Go through the telephone book and keep dialing! Also, you might try the local courts and ask there about what to do and how to go about it. Failing that, call the police and ask for their advice. If it was me, I wouldn't stop until I had an idea of what to do next. In the meantime, find out what you can about your son's father: his workplace, address, etc., etc.