My son is 6 montsh today :) his father has spent a whole $20.00 and has not seen him in 3 weeks. That's when we broke up, He never bonded or acknowledge him when we were together. Every time I ask him to please change his name he won't. Is there a time frame that if he doesn't see him or call that I don't need his signature to change his name?
I feel that he doesn't deserve for my son to have his name.

If both parents do not agree about the names by which a child is to be known, they can apply to court for the judge to decide (but this would still not affect the name on the birth certificate). An application to the court to change a child's surname is normally only successful when everyone who has parental responsibility for the child has given written consent.

Changing the name on your child's birth certificate will require re-registering the birth. This will only be allowed in certain limited circumstances, for example, if the natural parents marry each other at a later date. In other circumstances, if both parents agree, a child's birth certificate can be changed if the child's surname is being changed from the mother's surname to the father's surname.

However if the child was registered with the father's surname, it is not possible to change the child's surname back to the mother's on the birth certificate.

My son has had no contact with his father for 2 an a half years I have total parental rights of my son and I want to change his last name back to my last name how do I go about this an can I do it

You can go to court and force the father to give up his parental rights and then you should be able to change the name. I have heard from friends that they did this. And I do believe that you can change the child's name to anything even if it was originally the fathers name. In fact it doesn't even have to be your last name... you can make it be whatever you want it to be not sure why you would do that though but to each his own.

First you make sure you have a child custody agreement in place, and next you make sure you are enforcing the child support agreement.