Unauthorised deduction and arrogant attitude

I got into arrears with my credit card, and made an agreement in September with Nedbank to pay R660 per month on the amount . I paid October's installment early (29 Sept), and was about to make November's payment when I found they had deducted R2400 from my cheque account without my permission. I queried it and was told that because October's payment was made early, in September and not in October, they will treat it as if if no October payment was made. I am thus considered as being in default. No attempt was made to contact me about this so-called "arrears", and I don't know how they arrived at a figure of R2400. Assuming I had missed a payment, then R660 x 2 comes to R1320, *NOT* R2400. Their actions are ********* and vindictive, and they have left my child and me with almost nothing to live on for the rest of the month. They have shrugged it off and said that they will not be refunding this amount. Beware of doing business with Nedbank - they are notorious for gouging funds out of clients' accounts without permission. Google it and see. And don't make the mistake of doing any payments early, as they will happily take that and then grab even more when the date ticks over to a new month. I am closing my accounts tomorrow and moving to another bank, where I will be servicing my credit card debt ON MY OWN TERMS, as per my original agreement, and where my funds will be out of reach of their filthy claws. I have asked them for a complaint reference number so I can lodge a complaint with the banking ombudsman, but have not as yet had the courtesy of a reply.