Charging me for services I did not authorise

We are being billed for services my company did not order. Telkom refuses to take it off the bill, and refuses to cancel the services. I have gone to their branch multiple times, and called multiple times. I have submitted all paperwork required, and canceled the services multiple times. When I am at the branch (Gateway), they tell me not to worry, it will be resolved, but nothing happens. Every month I get the bill, and it is there again. I called in to see what the status is, and the person I spoke t told me that my dispute had been rejected! I went back to the branch and opened a new case. They assured me it would be sorted. The man who setup our account admits we did not order this, and it is clear in our paperwork that we did not order this, yet their head office will not take it off the bill, and they will not stop charging me for it. This is unacceptable business practice! You cannot bill me for services that I did not authorize. It is *****, and it is *******. Someone must be held liable for this. I am considering legal action, if this matter is not resolved immediately.