MTN unauthorised 24 month contract

I contacted MTN after my 2 years contract was finished and clearly advised them that i wanted the contract on a month to month basis however this was not done and MTN reinstated the contract for another 24 months without my knowledge .I only found out this when i went to do an upgrade at a MTN shop by the consultant who couldnt assist me with the application as there was an existing contract which i never knew .This is not the first time i had problems with MTN with regards to data being forfeited, the change of their billing dates and now i have a contract which i never knew existed.Their consultants dont know how to assist with queries professional and never ever call back with a response.This is so frustrating and can go on but i am honestly feed up with the way MTN treat their customers. I wonder how long they will take to sort my unauthorised contract???I will be stopping all payments to MTN and will try and get my bank to assist with reversing some payments made to MTN

VEE