Unsatisfactory service

Good day, I know this is cliché, but I have literally been an MTN customer since 1992!! They have just never managed to get my method of payment right. In the past, I experienced problems with salaries not being paid on time, so I changed my payment method to 'cash' and made payments via internet banking. When I renewed my contract in January 2020, I changed the payment method back to debit order and supp**** banking details as well as the date that my account needs to be debited, which is THE LAST DAY OF THE MONTH, as this is when my salary gets paid. Since the renewal of the contract, the debit order has never gone off and they continue to suspend my service on the 28th of each month!!! In July, we had death in the family, and I was not able to contact anyone because of this inconvenience. I went in to the branch in August 2020 and a very arrogant Brian insinuated that I did not have the funds to maintain my account and told me that I had given incorrect banking details which is why the debit order never went off. I know that that is incorrect, as I have used the same bank account since 2012. On 28 Septemeber I had to contact the call centre once again to unsuspend my service Yesterday, the same thing happened!! I contacted them, was told to pay R35 which was an amount on 60 DAYS, and said that as per my contract, I can pay the balance on the last day of the month. I paid the R35, they unsuspended the service and I got a message this morning thanking me for the notification of payment. When I tried to make a call this morning, I discovered that my service was suspended AGAIN. When I called the call centre, the consultant said that the R35 was not reflecting on their side. I don't understand how they receive a notification but suspend the service anyway, and I made the payment from they same bank as MTN!!! This is very inconvenient and terrible customer service, I am very disappointed,