AIU Weston, FL Ripped me off for more money Weston, Florida

I attended AIU in 2002 & 2003. Their advisor for 2 sections of classes told me I was approved to take 4 classes. It after the 2nd set of classes I received a bill for $5000 stating I owed AIU that money because I wasn't approved to take that many classes. After going to admissions and arguing my situation I was told it was their error and they would take care of it. So I continued taking my classes ( the correct amount ). They even offered me a student job. So I continue with schooling for another year. Then I moved to NJ and decided to try online class. That wasn't working out for me so I quit school. A couple months after a dropped out, I received a call from a collection agency for the $5000. I way floored. I'm not giving them any more money so now to go back to school, I have to start over because they won't transfer my credits. But I still have to pay $20,000 dollars for credits I can have. I've called the people that said they would fix the bill because it was their error isn't working there anymore and the President (a new one) will not return my calls. So if their is a recourse that is available to rectify this situation please let me know.

Thank you