Double Debit and useless complaint resolution

Very bad service in general. I have had my account debited for double the amount due by nedbank. I called and rectified. They said they would refund me. I received the refund and then the same amount debited again! I find this unacceptable after the issue was already raised and said to be rectified. It seems that the competence levels are very low as I really cant logically justify this. I called in today to rectify the SECOND error and the call centre tells me I have to wait for turnaround times again. Due to Nedbanks error and failure to provide any sort of resolution, I get a "sorry for the inconvenience" and told to wait for the appropriate dept to rectify. I will be changing banks soon.