Poor customer service-Debit order date not changed.

On the 30december I spoke to Noxolo to change my debit order date to the 07th of every month and she confirmed that it has changed.To my surprise every the 26th debit order goes through.This is not acceptable.The amount I should pay now is R452.58 and I decided to use self service to pay,it has now changed to R1021.i spoke to Kgomotso and she told me they have already added amount for next month.This is frustrating.I am not happy at all this needs to be fixed with immediate effect.