VEHICLE TRADED BUT STILL LIABLE FOR PAYMENT

Good day. I traded in my current vehicle financed by Wesbank at Suzuki Ipop JHB South on Monday and took delivery of my new vehicle which I purchased and financed through Wesbank as well. I phoned Wesbank accounts today to ensure my debit order for my previous vehicle is cancelled and does not get debited at the end of the month (debit order date the 1st of every month). The lady advised me that the account is still reflecting as open and if the dealership does not make payment before the 1st the debit will still go off and I will be held liable for the payment. How does this become my problem??? I have traded my old vehicle and took delivery of the new vehicle but still I am liable for the old vehicles payments???? The Suzuki Ipop dealership is one of Wesbank's dealerships and they should surely ensure and follow up the that the dealership pay's the money that is owed. Please assist me urgently