Student Loans

My wife is currently trying to resolve an issue with a student loan from a while back. She signed papers approveing her for "up to" $10,000 for school. The school aquired the full 10k loan and issued bits and pieces of it to my wife as needed while attending classes. She used only $6,000 but the department of education says she owes the full $10,000 plus a healthy ammount of interest. The school has since shut down, and during an investigation reguarding the schools misappropriation of funds, a majority of the records were destroyed in a fire. We have provided all of the records that we have to proove that only 6k was issued but are being told by the department of education that our documentation carries no weight in the matter and that she is liable for the full ammount since it was issued to the school. We have requested copies of the original loan agreement as well as any other paperwork pertaining the issue but are being told that will not happen. Any advise would be appreciated, the current ammount owed is over $12,000 and that is after paying more than $7,000 over the past couple of years.