Trade-in Car not settled for 2 months

I traded-in a VW Polo bluemotion 1.2TDI. The car has not been settled for two months. As a result two installment were *******ly deducted from my account by standard bank. The VW dealership manager and accounts have failed to resolve the matter. I view this as gross negligence or incompetence. I need the 6800 that was *******ly deducted from my account as a matter of urgency.