MFC taking unauthorized payments!!!

I have vehicle finance with MFC a division of Nedbank. My instalment payment was due to unforeseen circumstances late this month. I send an email to MFC to make arrangements for bringing my account up to date but in the meantime paid the account up to date well before the arrangement date. Despite paying my account up to date a debit was put through my current account with Nedbank for an amount not related to my instalment at all, in fact the amount put through cleared out my whole balance on my current account leaving me with exactly R1.58. When calling MFC the consultant that processed the payment is not available and I was advised that they do not know what it was for as they did not even put a note on the system as a reason. NO REASON is the answer!!! Off cause Nedbank gladly reverse debit orders on your current account when you instruct them to, but because MFC is a division of Nedbank they refuse to reverse the order. I am surely changing my current account to a bank that will carry out instructions on my account, and it will be the very last time I am financing with MFC. So be aware they empty your bank account without authorization and Nedbank banking allows it!!