Disappointed client

I got a home wifi router with mtn for 24 month contract and a month (November 2023) before the contract ended, i called in to cancel the contract and got a reference number for the call. I called again on the 15th of December and was assured that the contract was cancelled only to receive another bill for the following month for the said same contract, then i emailed mtn customer service countless times but to no joy as no one assisted me in actual fact. I called again today 29 December, only to find out that they never actually cancelled the contract which is appalling meaning i have to pay for a bill i never should have received due to the incompetence of their staff members. My business and i will not be using mtn in future as this service is just unacceptable.