MFC f**** my account

My vehicle was settled on the 23rd of November 2015 and on the 25th, the debit order for R14900 went through against that vehicle which was settled. I went to Nedbank to see if I can reverse he debit order and I was told about how they don't reverse debit orders of Nedbank or its Divisions regardless of the situation. Because of this debit order which was not planned or budgeted for, my bank account had to suffer a minus balance. All my debit orders which were not Nedbank related were returned including one of MFC's on my other vehicle. When I called their call centre, I was told that the refund might take 10 working days as it needs to be verified first. While on the issue of the refund, I was also reminded about my other vehicle account which was returned. I made arrangements with the call centre to manually debit my account on the 28 of November as I would arrange for get some funds into my bank account. To my surprise the next day MFC decided to take all my money. My account was debited twice, manually and that magtape order. But how do they do such a thing without consulting with you? Now I must wait for another 10 days to have my money? Almost R20k that they took!