Changing account number is a disaster

I changed my account number and was in the process of changing all relevant debit orders/informing accounts of new changes, all went extremely quick and efficient excluding ABSA. I did everything that was needed of me yet they do not receive any documents and still have my old information. I resent these docs 5 times and still no response, but I am sure when debit day comes and it is not successful, I will be in trouble. Please fix this.