Telkom cancellation impossible

Cancelling an account with Telkom proved to be a much more difficult task than with any other service provider. They are very quick to install a fiber line as well as do upgrades, but when doing downgrades or cancellations they have no service at all. After cancelling my service in March online (as they so proudly claim possible on their website) I still had no luck and this line is still active and they keep on charging me.