Billiong, Cancellations and everything pathetic!

Telkom has been billing me for a device that I did not sign up from March 2018, their cancellation department is not existent as they continue to direct me from pillar to post with endless logged disputes! it is now October and I still receive invoices on my Telkom account, I received an email from their accounts manager saying the issue will be resolved but it still hasnt! Telkoms service pathetic! no one know what to do and its very annoying to say the least as the supervisors also don't know what to do. Do NOT sign up for anything with Telkom, it gives EVERYONE trouble