Don't ever use Telkom as a service provider! Biggest mistake you will ever make

How does a person actually end a contract with these people!!! I'm still being billed months after the contract was canceled and everytime I call them to confirm that the the contract is canceled and question why I am still being billed. That's the date they use as a cancelation date. So then they bill me for another 2 months because according to them the account was still active. I just want to be done with them!! It's like the gift that keeps on ****ing giving...