Trying to cancel Telkom LTE contract that's run it's 24 months...with no luck

I've been trying to cancel my Telkom Wireless Broadband uncapped subscription since January 2018. I submitted the necessary documentation and did not hear a thing back from Telkom. But diligently, every month they run their debit order. On the 24 month anniversary I tried to change the contract and Telkom *****ed up. Instead they renewed the subscription. Right now I don't get the LTE coverage since I've moved from where I used to live when I took out the contract. I'm paying every month and basically my service has stopped working for a month now. Telkom shops can't help you. They just direct you back to the call center, which is impossible to get hold of. And they in any case direct you to sending a form to an unattended mailbox, nobody from the cancellations department ever gets back to you. I'm tired of paying for a service I have no use for anymore.