Sounds like this going to take a trip to court to enforce child support, legal guardianship, etc.
You can also call Child Protective Services if he's been abused, but be aware they can take him from you and put him in the care of strangers....the police could be called, but if there are no marks or other evidence, it may be fruitless.
Any legal aid help in your area? I'd call the local county courthouse and find out. Good luck...seems the child is lucky to have you in his corner.