You basically will have to prove you didn't get the money or it wasn't used on your behalf. So first log on to nslds.ed.gov and enter your personal info and find which loans they are, disbursement dates, amounts, etc. Then you will need to see where they were sent, generally what happens is students apply to a school then don't go, funds are disbursed and the school doesn't send back money if you didn't withdraw or inform that you no longer had the intent to attend. There are a lot of varying factors, if you would like more info specifically to your situation, I am more than happy to help, email me directly. firstname.lastname@example.org I don't mind giving you more info, but depending on many variables, there may be different outcomes and info I'd suggest to do. It's easier to be able to ask info directly in order to provide you the best option.
I do this for a living.