Dissatisfaction with basic service to end contract.

As per my contract details I am supposed to give MTN written notice that I will be continuing with my contract ending after 2 years. I am currently living overseas, and they have not been helpful at all. I have been asking who I need to submit this written notice to and no one has been forthcoming. The one email I received from Nhlankanipho Ntazi, said they are trying to call me. I told them I need to work via email because I can't take calls during work hours and because of the time difference between SA and the UK. I am terribly disappointed that I have to beg to do what they literally informed me to do to ensure that this contract will be stopped. I am at my wits ends!