Traded in a car and the debt has not been settled.

I traded in my car with Hyundai on the 9th of February 2024.On the 27th of February 2024 Wesbank is calling me saying the account has not been cleared and I have to pay an instalment for a car that I dont have.They are telling me that I must speak to Hyundai but Hyundai says they have settled the account.I need Hyundai to help me maintain my dire credit record.