poor upgrade and cancelation process

I am extremely dissatisfied with how my recent contract upgrade was handled. Despite upgrading, my contract was not cancelled as expected, but instead converted to a month-to-month plan at almost triple the original price. Given my previous cancellation issues, I'm appalled as this seems to be a recurring practice.I will be making a constuted efforrt to cancel all current contracts with MTN and never ever take a contract with them again.