Early debit order not reversed

I have a personal loan with Nedbank and every month the debit order goes off on the last day of the month, however this month (December) the debit order went off on the 18th of December without any prior notice and without my consent. On 19 December 2015 I then called the personal loans department (case number ***) and I spoke to Ayanda who assured me that he has submitted a request for a reversal to take place on the same day (19 Dec) as I wanted the reversal to take place immediately and my pay date has not changed. <br> <br> Today is 21 December 2015 and the reversal has still not been done. I have commitments that I could not honour due to this inconvenience. Having being a client for many years with Nedbank I feel that I should actually shift banks as this is absolutely unacceptable. I have a home loan, cheque account, and my cars are financed through Nedbank. <br> <br> I need this matter resolved as a matter of urgency and I need to know why I was assured that a reversal would take place if in actual fact it would not take place.