Cancellation of contract ignored

I sent my written notice of cancellation on my contract in April, as per the terms of the contract. I have also followed up to receive a written notice from MTN that they did indeed cancel my contract, but no response was given. Also with the recent strike the call centre was cutting off my calls. So today I got through to a consultant and I must be honest I was not surprised that my communication regarding the cancellation was ignored, as they have no record of this notice. I feel for the agent, Andrew, as well as all the other call centre agent in the telecommunication industry as they have to bear the brunt of the public's frustration regarding the industry with probably the worst customer service in the private sector.<br> So Andrew escalated my query and frustrations and now I will wait with interest to see if my contract will be cancelled with no charge. What is interesting is that my service has been cancelled from 13 June 2015, so the assumption would be that they did cancel my contract?