Unauthorized debit order date

I have contracts with Telkom mobile which has been running for over 24 months that includes 3 different devices/packages (2 mobiles and 1 router) which all have the same debit order date which is the last day of the month. Noting that throughout my relationship with Telkom I have never missed a payment/debit order.

My contract debit order date was changed from the last day of each month to the 15th day of each month without my consent as at 15 August 2020. I noted the following activities by Telkom on my bank statement. 31 July 2020: telkom debits my account with R499 which is correct and on the correct dates. 15 August 2020: telkom debits my account with R499 15 August 2020: The amount of R499 is auto reversed and my account credited with R499 with a reason (RTD-Not provided for) 25 August 2020: telkom debits my account with R499 which is correct and on the correct dates. On the 6 September 2020 I received my telkom invoice via email. The invoice notes that my bank account will be debited with R1200.70 on the 15 September 2020. the invoice is broken up with the below details: 01 August 20: Balance bought forward R499 15 August 20: Payment: Thank you: -R499 18 August 20: Payment rejection: R499 01 Sept 20: Invoice for august: R701.70 (which includes account subscriptions and once off charges of R202.70 that I know nothing about).

On 07 Sept 2020 I called the customer care line and spoke to a very helpful and patient call centre agent (Siyabonga Khumalo). I noted to him all the above concerns and he went on to investigate my account he picked up that my debit order date was actually changed on the system, I noted to him that I have not requested or nor gave consent for my debit order date to be changed from the last day of the month to the 15th of each month. He noted that there are two call centre agents who called me during the month of august 2020 and I remember the calls because they called reminding that one of my devices was due for an upgrade on both calls I indicated that I would not be renewing that particular device that is expiring on the 06 Oct 2020. He noted that both call centre agents did not leave any notes on the system and he is therefore unable to see which of the two actioned the change of debit order date and he had to log a request that the phone calls be listened to, to determine who did this without my consent.

I am left frustrated as Siya indicated that he is not sure if the unauthorized debit order will still go off from my account on the 15th of September as this matter is still to be unattended to. I am very dissatisfied with all this as debit order details which affect my bank account and credit record are happening without my knowledge and consent, furthermore I still have to be inconvenienced due to telkom's lack of internal controls and failed processes.

I would appropriate that the above matter please be attended to and remediated to ensure that on the 15 September 2020 my bank account is not impacted by this unauthorized debit change date which is meant to only go off at the end of each month.