Unable to cancel expired contract

I have had the most ********** service in trying to cancel my home router contract with MTN. The router stopped working about 6 months ago. I took it to the store and they were unable to fix it as it needed to be sent to their lab. I have not seen the router since and have unsuccessfully requested on multiple occasions that the contract be cancelled through the retentions line given to me by customer service.

They have now advised me that I need to go in store to cancel. I cannot believe in this digital age that I have to physically go into a store to cancel a contract I have been receiving zero value out of. The contract has also since expired and yet my notice to cancel seems to make no difference.

MTN - you are like a bad boyfriend that I just cannot get rid of!!!