Mtn charging me a cancelation fee for a month to month contract

I had mtn home wifi contract, started having network issues and their network coverage department couldn't assist me. After countless back and forth with their call center and branch in festival mall, I managed to get a branch that assisted me with canceling and told me to pay a canceling fee of R307 because they have already loaded data for September, data which I couldn't use anyway because there is no network and I dropped off the router at the branch. I paid the fee to cancel and get them of my back, now mtn wants me to pay another R295 for the month of October, mind you I don't have the router I returned their router so why am I paying for October. I regret getting a contract with them, I won't pay for this