MTN Contracts Dishonesty

I have a contract with MTN that ends end of October. I have been calling their call center since 3weeks ago and I was advised if i don't want the contract to continue after the 26th October I should call 30days before. I called them on Friday they said its not the 26th yet i should call in on the 26th I called on the 26th of September i was told I should call in on the day the contact ends. This is a lie because i know the day the contact ends they are going to say its too late for you to cancel as I have had that experience before because they know once the contract ends, it automatically puts the customer in the moth to month contract and they charge you more than what they contract was charging initially.

I have ran out of options I don't know what to do to stop MTN from what they are doing