Kaplan University Harassment for funds Internet

 I was a student at Kaplan from 2014 to Jan. Of 2015. I withdrew due to health issues and decided taking a break would be best. After withdrawing they began calling multiple times a day to collect funds for a class at $544 for one week. They told me I could not return until I paid the amount. Several days later I received an email saying I could pay off my loans using a portion of my financial aid if I filled out the papers and returned them within a week. I did it the very next day. Since then I have gotten no response to the papers I sent in. I am getting harassing calls multiple times a day even though I block the numbers they call from different numbers and locations to get through. I have now resorted to threatening them with a lawyer. I have sent multiple emails to financial aid asking about the papers I sent in and every email has been ignored. I even sent copies of the emails they sent along with mine. Nothing. I think I'd like to find a class action suit to get in on to get them to leave me alone.