Incorrect Debit order date

I had the same problem with Nedbank in the past about the very same problem, We agreed that they will debit their premium on the 1st of every month, but now I see that they just debit on their own chosen date which was the 2nd. I don't understand because the 1st of the month was on a Wednesday, WHY WAS I DEBITED ON THE SECOND AND 2 PREMIUMS INSTEAD OF 1.. then you charge my account the R125 X2 unpaid debit order charge... PLEASE REVERSE THE CHARGES on my account, Its not my fault that you guys debit whenever you feel like it and there is no SMS notification for these transactions..