Can I file a lawsuit against a college that is wrongfully charging me for a class I never took?

Can I file a lawsuit against a college that is wrongfully charging me for a class I never took much less registered for? They are claiming I registered for the classes (when I was told I didn't have enough information to register,) on a date I wasn't even living near that campus anymore. I ended up taking my two old jobs back and working during that semester, 65miles away from this campus. I was told that I wasn't registered for this class the day I went in to register because I was missing shot records and test scores, the lady helping me out told me I couldn't attend classes until I returned with this information. Certain and I was forced to move back to my home town and retake my old jobs. She had assured me I was not registered and I still had the signed paperwork I was supposed to return with shot records and test scores. Now I am receivables from a collection agency for these classes. I called to straighten things out with the college only to have the women I was talking to ask how I could make an A in a class I didn't attend? The other three classes I was a no-show and I should have been for this class as well considering I never attended it. I replied, "I don't know how I made an A in a class I never attended but I have proof I was working 65miles away and couldn't attend this class." They retorted, "Who were you sending in your place?" I replied I hadn't sent anyone in my place and mentioned that the professor who had the class should have a sign in sheet, but now the professor they gave me the number for will not return my phone calls and they refuse the remove the charges. What is scary is I made an A in a class I never took for nursing. They graduate LVN's RN's and other medical positions every year, I'm now worried about seeing any of these graduates, how do I know they really earned that diploma, certificate, or other proof of graduating. Should I also call someone to investigate this college?