Telkom cancellation problem and then incorrectly billed for no service after cancellation

Account no *** EFT Ref No *** I cancelled my ADSL contract end of April, with 1 month notice for end of May 2021. This was not done in time and I really struggled to get someone who finally assisted.

She logged a dispute to stop the debit order for not going off in June, but this was not done. I was billed for a full month again, without having service. No dispute has been resolved and more than 5 have been logged.

Why is this such a problem to resolve this issue?