Cell C don't want to cancel my contract

Cancellation of my cellphone contract:

My 2yr contract with Cell C it expires on the 30th Nov 2018. On the 23 Nov 2018, I received a call from the Cell C sales agent by the name of Jonathan Smith. He came with different offers for me and after a long discussion I agreed to upgrade.

An hour later, I called in to cancel the contractor same time stopping the delivery of the phone..that is where the problem started..to date no confirmation from Cell C about cancellation of my contract. I requested for email address, I was told there is no cancellation via email.

The contract was cancelled on the 23 Nov 2018 but no one ever confirmed that...No one is willing to assist as I have been taken from a pillar to post..

I am frustrated..just want to see myself out of this abusive relationship..