My sister made a verbal agreement with a family friend that she would continue paying a auto loan in exchange for the car. She also paid an up front amount. She continued making payments for the car for two years directly to the auto lender, of which she has proof and is listed as a contact with them. She was finally able to pay off the auto loan, and the title was recently sent to the family friend. It seems that the person want's to back-out of the verbal agreement after my sister paid off the car. We are talking about thousands of dollars. Can this person back out of the verbal agreement? If he does, can we sue the person to obtain the car title? What can we do to fix this mess?