Bad billing experience

The service at Telkom is extremely bad. I cancelled an LTE Wifi installation within their 7 day cool off period. A month later Telkom handed me over to their attorneys for debt collection. First they wanted me to pay a cancellation fee, then when I call their customer service centre they removed the cancellation fee. I learned few weeks later that they activated the account. Their attorneys wants me to pay monthly instalments for a service that was never installed in my house. Every time I call to follow up with the Telkom they issue me with a new case number and a promise to resolve the issue. It's been 3 months now and nothing has been done.