Bad service from Audi Financial Services

My vehicle was financed by Audi financial services and I was now left with final payment for 2300. I have been paying 7300 for the past 5 years and the final payment is supposed to be 2300.The statement shows that the balance is 2300 however they debit my account the full 7300.I have been calling financial services and given different reasons why the full amount was debited instead of the balance. I was advised that the amount will be credited back to my account within 48 hours. It is now 10 days later and I still have not received the payment. Talk about bad service and inconvenience for my money. I have to call them every second day for my money to be returned to me.When you call them they advise that their calls are recorded. I wonder what are they recording when their service is so bad. 10 days later and still no refund