Worst service. Cannot cancel a line.

I've been trying to cancel my old Telkom line and I don't understand why I'm still being billed for it. I've cancelled this particular line according to my knowledge on 12 October and have references for this online cancellation. I've contacted support via twitter, who have confirmed that the cancellation would happen by 12 November. Only for me to receive another bill in December billing for a period after that which I had already cancelled. Now I'm being told my active line will be cut because of not paying a line I've cancelled and don't even use. What is this nonsense?