I wanted to update those who commented or give help to anyone who's in the same situation.

I went to court last week and the agreement we made was not valid because no court or judge signed off on it. So I was not held to that. Also, I did not get any of the $2500 that I've paid out since June. They did stop my child support payments and have arranged for her to pay now. However, they only made it retroactive to August, not June. The reason behind that is every year my son usually spends most of the summer with me anyway and the court sees this year as no different. As of now, she is in arrears and will be paying child support.

The court did ask her where she spent the money that she received from me since she didn't have our son. She said she could not explain it.

I will say that the system set up for child support and fathers is an unjust one. I could have just as easily given $2500 to a stranger on the street and they would have done the same thing with it that she did... spend it on themselves. Either way my child didn't see a penny of it. Sort of defeats the purpose of "child support". But I'm glad things are over. It was a long road.