Legal advice, please!?

I was told over 10 years ago, that if I surrendered a vehicle my outstanding balance would be dropped. I was told someone would contact me with directions for delivering the car. I never signed anything, this was a verbal agreement before a hearing (not before a judge) with a FMC rep. I was told I didn't have to attend the hearing, that I could leave. Three weeks later, they reposessed my car and stuck me with the past due balance. When I contacted them, they said (of course) they didn't show any records of such a verbal agreement. I didn't even have the name of the woman I discussed this with at the hearing, the entire conversation took less than 15 minutes. I am sure they either knew what they were going to do all along or decided to reposess anyway since I (ignorantly) did not get this agreement in writing! I never got a lawyer because I thought it was a losing battle. Do I have any rights? They are still asking me to pay this bad debt.