Impossible Telkom

I have had the absolute worst experience with Telkom. I have been billed incorrectly for 3 months in a row and when I try to cancel my contract, I'm completely ignored. It's like the staff is instructed to, at all times, make a contract cancellation as difficult as humanly possible. I even tweeted them and have received no response. I just want to be rid of this. Someone please help!!!!!