No Communication to contact emails and visits

I visited the MTN Northgate Service Centre on Tuesday 31 March to cancel a long-standing contract with MTN effective from 30 April. Despite visits to their centres and various emails I have not had the courtesy of any confirmation that this contract will be terminated. I have tried twice in the last two weeks to see why the contract has not been terminated and even put credits into the system for voice and data (which seem pointless given the fact that I can't get out of the contract). Perhaps when access to the debit account is denied I will get a response? All emails on file for reference purposes. I cannot explain the discourteous manner in which I have been treated but certainly understand why I have to move away from them as a service provider.