Not doing what customers request

One of my contracts was about to expire and i was told over the phone that i had to go into a cell c shop to cancel the contract. After driving to a shop i was told inside the shop that they could not cancel the contract and that i would have to phone 084 145. I then phoned them on the 20 March 2019 to cancel. Just to find out end of this month that the contract was not cancelled. I was told that they could c that there was a cancellation logged but not processed. I have requested the recording for the 20 March i made but up to now still nothing received nor a phone call to get this issue resolved. So for now im still paying this contract. Best is im now getting a quarter of the data for something like R100 less than what i was paying. I want this resolved and my money refunded ASAP.