COLLEGE OVERPAID ME STUDENT LOANS

In August my school, USC, gave me my student loans, like normal. In October I received an email saying I owed them about $9000. I thought this was an error so I contacted Financial Aid via email. They told me that the school had made an error which resulted in an overpayment and that I now owe them $9000 or else I will be barred from enrolling and graduating. I have spoken with every department and they all say that yes, it was their fault but I still need to pay them back. Is there anything I can do? Is this fraud? Ideally I would like to defer the payment to go along with my student loans in the future, I don't see that because of their mistake it is stopping me from getting my credential needed to make money to pay them back.