Debtor Education Vendors

I am a 70 year old male. Back in 2001 someone used my ID to go to the Univerisity of Phoenix online. And it was not me. My social security check was attached, but then when I contacted the people and told them that it was not me, they stopped. Then all of a sudden my Income Tax Refund was taken. I had to work part time to help with my medical bills and mortgage payment.
I called the school and talked to this one person who actually got smart with me.
Its a shame that people can do whatever they want to people and get away with it.
What can I do to get my money back?