cancellation of contract - no service from MTN

An upgrade was done on a contract on the 5th of March at MTN direct on the same day I requested the contract to be cancelled. Its is now the 24th of May 2018 and the cancellation of the upgrade has not been done.

Called MTN direct on a weekly basis since I requested the cancellation but no one can help me except the sales person who did the initial upgrade. Cannot get hold of him directly, have no direct email add or telephone number to to that. I ask to be put through to him Devashen but he is always on a call and that he will return my call. To date no one from MTN has returned my call to resolve. On the 25th of April, i called MTN direct and spoke to Renell Pillay at MTN direct and she advised that the upgrade was cancelled. Received my bill today and still reflects the full upgrade charge and no credit were given.