Mtn Stating I should be Deceased in order to Cancel Month to Month plan

I took out a month to month contract at an Mtn stores 36 West St, Durban Central, Durban 4001. Went in the store 3/10/2024 to cancel and made a payment to cover my billing cycle. 5/11/2024 on my billing date I get a notification about a cancelled direct debit trying to take a payment and it was Mtn. I went to the branch in Umhlanga and was told the month to month plan has not been cancelled this ticket to cancel was cancelled on the 10/10/2024 however I have text advising it was cancelled on the 5/10/2024. And Mtn never notified me when my cancellation did not happen. I am not happy and I have gone to the branches Twice in November and yet no one has helped me and Mtn doesn’t have a direct line of communication the staff is very rude at the Cbd branch and I’m tired of being laughed at. The missed direct debit has affected my credit score