Complaint Review: american professional institute

I attended API in 2011 starting in Feb. of that year and was forced out of school in june of that year. I have a debt with the financial aid department because they received money for me for the time i was attending the school. I had a death in my family and i wasn't attending school for two weeks and within the two weeks i received a letter stating that i was withdrawn from school. I went into the school to fix the situation they said i couldn't attend school and i asked why not they told me that i was already withdrawn at that point i asked about the refund they said they sent it back. I received a notice about being in debt for the amount 3500.00. I called the school and they insist that they sent it back if they sent it back than i shouldn't have this much debt and interest has been made on this amount.