Unhappy- ABSA Homeloan

Good day ABSA Homeloan,

My mother has a Homeloan account which I have taken over. Towards the end of August I spoke to an agent and advised that I would like to activate the debit order and change the payment date to the 25th instead of the 4th. I send the required forms on the 28th August. The email received advised that the changes should be done after the 4th . On the 25th September my account was debited, I assumed that the changes have been made. On the 6th October I received a call advising that the account was in arrears. I tried to explain to the agent that I have requested this to be changed and my account was already debited on the 25th and will be debited again on the 25th October. The agent was very rude and did not want to listen as I explained the conversation that I had with the agent in August. To my suprised my account was then debited on the 7th October. I then resend the same forms that I had send previously with my banking details. I do not want to be spoken to like someone who is refusing to pay the account and spoken to in that manner. I was in return very rude to this agent because she was not even trying to understand or help. Can someone please explain to me what is going on here because this is very frustrating.