Telkom failure to communicate regarding cancellation

I've been trying to get Telkom to cancel my mobile data account since June. They have acknowledged my cancellation request but have not cancelled and I've been calling each month to have them resolved, even tweeted them (https://twitter.com/areadblackgirl/status/***?s=21). Someone came back to.me after the tweet and asked for my details and that was it. I emailed them back last week, nothing. I'm extremely frustrated about being billed over and over for an account that's not in use, that I asked to be cancelled long ago because I upgraded to fibre and nothing is happening and no one on the phone can sort it out.