Student Loan

I had student loans in the early 80's. I paid one but defaulted the other. I declared bankruptcy in 1990 and it was released. collection agencies claimed it was impossible. They finally started calling my work and threatening me so I started a pmnt plan. After about 10 months and lots of research I wrote a letter with copies of my Bankruptcy to the Dept Of Ed. They released my obligation and said it did go through in Bankruptcy - the last year it was allowed. I was extremely happy but they also told me since I "voluntarily" hgave those payments I could not get the money back. So, where does the money go? Can I pick someone to help out? This just seems ridiculous when I was told for 20 years there was no such thing as a Bankruptcy with Student Loans.