UNACCEPTABLE WESBANK

I am totally fed up with the abysmal service provided by Wesbank I settled a HP agreement, yet Wesbank has deducted, not 1 but 2 further instalments, which are sitting in the account, resulting a credit balance. I have sent countless emails, every time, a different person responds, I have submitted FICA documentation, as they requested, yet still, over six weeks have passed since the vehicle was settled and still I can't get the funds back. It is ridiculous that an entity can hold on to funds that are not theirs. I have requested the matter to be escalated, yet nothing happens. I have requested feedback, yet nothing happens.