MTN retention department not answering calls

I have 2 contracts with MTN which is coming to an end. I do not wish to continue with the contracts. I have been trying to call MTN many times, chose the cancellation department, but nobody is answering. Every time an hour has passed. I even sent an email to their customer care to cancel, received an automated response, but still no reply with regards to the cancellation.

What a useless company