Useless Telkom

I asked Telkom to change my debit order from the 5th to the 15th of each month. They did not tell me that I will be debited on the 5th and the 15th of November 2022. I called the call centre aasking them to change my debit order date to the 5th again. i have called the call centre 6 times and they are not able to because their systems are not able to make debit order date change. I was given a reference number yesterday as the lady told me that she will ask billing to manually fix it and today I got a message advising me that my case to change the debit order to the 5th is resolved. I called the call centre to ask them to confrim the debit order and they advised that it is the 15th while my case reference number ***8 was closed. I was advised yesterday that there us no complaints policy and that your complaint department is Hello Peter. I just want to know how do you work with a system that is not able to make changes. your service as well as the service of your staff members is shocking. How do you close cases that you are not resolving, please help me understand.