Unable to cancel contract.

I have been unable to cancel my Telkom contract for months. I work abroad which adds more complications. I started a two contact with Telkom three years ago. I paid it off and still they kept deducting every month like clock work. I tried going myself in person (both in Port Elizabeth and Cape Town). I was told it was cancelled. I tried emailing but no response. I eventually asked my granddaughter to go on my behalf. They told her it is cancelled but one last debit order still needed it go off. It’s now been over five months I am paying a contract that is paid up.