Pathetic customer service

In the beginning of November 2020 I wanted to cancel a contract which was going to expire at the end of November. After going into an mtn store (where you can very easily take out a contract) I was told that I will not be able to cancel my contract in store, but rather had to phone mtn customer care to cancel. After speaking to a consultant I was told that someone will phone me back within 72 hours to confirm the cancelation. 72 hours passed and no one had phoned me back. I decided to phone them again to confirm the cancelation, but after being on hold for over 20 minutes, I hung up the phone. This happened about 2 or 3 times, so I decided to leave it.

Now, in the beginning of January 2021, when my debit order goes off, I see that not only was the contract not cancelled, but they also charged me an extra R1000, because the contract is no longer on the discounted rate. So once again I'm on the phone to mtn, and after checking, they confirmed that my contract is indeed still active! As this was quite early in the morning, there were no managers available to speak to, and they also refused to give me a name of a manager that I can speak to when phoning back later. So after phoning back later in the morning and explaining the same story to a manager, a ticket was logged for the credit of R1000, but I was told that I have to be put through to the right department to cancel the contract (the same department that doesn't answer the phone when you get put through to them). So after being on the phone for more than an hour and a half, somebody eventually answers the phone, only so that I cannot hear the person on the other side and the call gets dropped. Now my contract is still not cancelled, and I don't feel like sitting on the phone again for over an hour. Perhaps I should just cancel my mtn debit order, maybe they will get in contact with me then?