Telkom refuses to cancel my contract

I've been trying to cancel my contract services with Telkom for 3 months now, unsuccessful. I've been asked to pay the cancellation fees, which I did, but my account is still active and they are debiting every month.

The reason I cancelled was due to bad network coverage, I gave them a chance to fix the problem, but after months of waiting I decided to cancelling, now they won't let me cancel. I am not even using their device anymore. Stay away from Telkom, they offer bad service, but won't let you out of their contract when you've enough.

I've tried every avenue with them, no luck. Email, sms, calling, facebook and even chatrooms. nothing.