Unpaid vehicle loan
About 15 years ago my mum sold a vehicle. We have the paper work signed stating that the vehicle was sold but the bank loan was not transferred to the buyer. The person who bought the vehicle did not pay the loan at some point that we do not know of. We did not receive any calls or letters from the bank and had forgotten about it until recently. My mum found out about the unpaid loan recently because her bank account was frozen. What are my options?