Non conformance

Two years ago I traded a vehicle in at this garage and procured another vehicle. Traded a Tata Xonon 3.0 in on a Ford Bantam 1.6. I have spoken every month sometimes verbally sometimes per Whatsup with the owner of this garage about the settlement of the account on the Tata. I was assured that the account was settled but til this day, the vehicle is still on my name at Aarto and the financial institution. Every month this vehicles payment is deducted from my banking account and then the garage refunds me accordingly. Two years now it is back and forth concerning the settlement of this account. Paperwork were supp**** on the so called settlement but the account info on this paperwork was wrong. This was communicated with the owner whereby I was assured that it would be corrected. What am I to do in such a case.