Mtn does not want to cancel my contract

I’ve been trying to cancel my mtn contract sim for over a month,I took out the contract on 10th of March and I tried cancelling before 7 days but it’s still working,I’ve made numerous calls to Mtn and I keep getting told that my query is being escalated,how many times must it be escalated before it can be cancelled.Now I have to pay for 2 months when I wanted to cancel it before 7 days Mtn is so frustrating,I regret taking a contract with them