Telkom still billing me after cancellation of service

I cancelled my landline with Telkom on the 1st of Feb. I received an email informing me that it takes up to 21 business days. It is now the 9th of April and they are still sending me monthly bills for something that I am not using.

Telkom service is ********** and they do not care about their customers. The only thing they want is your money. And they will keep charging you even after you have cancelled.