Telkom not cancelling after acknowledging intent to cancel

I cancelled my Telkom account over a year ago and Telkom emailed their acknowledgement of the account. I have been in regular correspondence with them and they promised to escalate the matter after not effecting the cancellation. The end result after all the correspondence is that they have handed it over to the collections department and after communicating with them, it still hasn't been resolved. What needs to be done in order to have this issue resolved. They acknowledged the cancellation and didn't do anything about it and then we have to treated like ********* when Telkom isn't doing their work correctly. I would like to have someone from Telkom who can actually do something about it rectify this situation.