Need assistance with cancelling my MTN sub

I have been trying to cancel my subscription since the 6th of January. I however still need to keep my number. I keep getting assurance, first at the end of January and then at the end of February that it will be actioned and I still has not been cancelled.

Instead I keep getting calls from MTN to upgrade my account. When trying to explain to the consultant that my account needs to be cancelled, they cut the call on you. I have spent several hours on the phone with MTN with no assistance.