Annoying service from Telkom

I am extremely annoyed with Telkom. I cancelled my data contract last year September (26/09/2019) after not succeeding to do so at the very shop where I'd opened the account (Telkom Woodlands). The account was over 2 years and was running month to month. I received a confirmation email indicating the mandatory 30-day account cancellation period. But almost 190 days later, the account is still running and I am being billed. I know this was a lucrative account for Telkom but I'm not gonna allow them to abuse me like this. The times are hard for all of us but I ain't gonna be servicing this account. Nope. Nada.