MTN not allowing me to cancel my contract

MTN is not allowing me to put a hold on the cancellation of my contract. This is an example of how the mobile operators in South Africa create rules in order to keep their clients stuck in unnecessary cellphone contracts. How is it possible that I am not allowed to flag my intention to cancel contract at the end of April 2020. This must be ******* and against the core of practice of the competition commission. Its pathetic