Reversal of settlement discount

I had an overdraft of R10 800 and paid an agreed settlement of R8800 in Sept 2015. Confirmation was sent to the bank and it's admin and recoveries units. In Nov money was deposited into this account though it was closed. The bank refused to reverse the fund back to the sender nor could I access it for a while. The freeze was lifted but I could not have all the money seeing they withhold the settlement difference of R2000 though bank official insisted that I could not be penailsed based on settlement difference. I have since been harassed by their call centre of R90 service fee owed to the bank yet my R2000 is kept. Money was again deposited into my account and again the bank took this too. I am not sure how to resolve this as bank officials and attorney tried to have my money returned, but to no avail.