University of Phoenix Ripped me off by charging me for two classes I did not take. tempe, Arizona

In 2008 i attended university of phoenix for one semester ( two classes). I dropped out of univ of phoenix after those two classes due to the decision that online learning was not for me. Univ of phoenix refunded the money from financial aid to them and ALSO charged me for two MORE classes that was next on my list. I had never attended these classes nor had I intended to. Univ of phoenix along with American Student Assistance have together been trying to charge me for over 4500$$ for "two" classes which I did not take. When I sent an email to Univ of Phoenix explaining the circumstances I was pretty much brushed off by a lady who told me I had attended those classes. I have paid off American Student Assistance but i refuse to pay off Univ Of Phoenix untill they can Prove to me that I had attended those classes, in which case they cannot because I know for a fact I did not attend those classes. I do not suggest anyone going to this so called University as they are a bunch of scam artists who should not be accredited.