DEBIT ORDER DUE DATE

I previously had a discussion with a ops/teamleader regarding my debit order date which in my comtract was agreed upon as the 25th of each month. I had a problem previously where money was taken out of my bank account before this date causing me a problem in the sense that the money that was in my account was to be used for something else. A reversal had to be done by them. This month the same thing happened whereby on the 23rd of November they went in for the money which was not in I now have to pay my bank for an unprovided for debit order. More importantly I settled the full loan before 25 November but on 25 November another debit order was attempted which my bank charged me for AGAIN. I would now like to request Nedbank to please refund the charged amounts as this is by no stretch of the imagination any fault of mine. I sent an e-mail to a consultant in the personal loans dept he just flat out ignored my e-mail by never responding to it Rodney Jacobs [Email Removed] is his name.