Poor service and unprofessional

I called MTN on the 06/01/25 to cancel one of my contracts which expired on the 16/01/25. The lady Ms Reddy gave me a reference number and assured me that she had processed my request. Today I received my bill and I am being billed for another full month for the very same contract. When I phoned MTN to query the guy tells me that the ticket is still open and the woman never closed it yet that's why I am still being billed. Now is this the kind of poor service you get from a big professional company like this. I have been a client for 18 years and I currently have 5 contracts with them. Now I am disgusted at this pathetic service. Actually I am not even upgrading I feel like canceling the rest of my contracts which are also due for upgrade. MTN never want to cancel any contracts they always finding excuses to ***** your money.