Billed three times, instead of twice.

I was late on my payment in December 2015, and for January 2016 but made arrangements to pay at the end of January 2016 after my salary came through. Thereafter they took out one payment on the 30th January 2016, straight after my salary got paid. They then went and took out a further two more payments on Monday the 1st February 2016. I called the call centre and lodged the claim, and they said the payment will be refunded and taken out of my account instead at the end of the month when I get paid again. Today I got an SMS stating that the request was not successful. This is BS as they take my money very quickly, but do not want to put my money back!!! Nedbank is terrible!!!