Overcharged and No Refund issued into my bank account

On the 31st of August, 3 DebiChecks went off on my bank account to the value of R716.90 each. On the 2nd of September I called their Call centre to request a refund and was told it will take 7 working days. After the 7 working days, I called again to query why hasn't my money been returned to me as they over charged me by more than R1000. They said I will have to wait another 7 working days as the refund takes 14 working days to complete. Today is the 15 working day but I still have not received my money. And I Specifically told them to refund it back to my personal bank account and not my Cartrack account. I am extremely dissatisfied with their service. Why should it take so long to do a refund. Its completely unacceptable.