MTN service pathetic

I emailed MTN (Note: I officially started enquiring in November 2019) to tell them that they had been charging me for a contract that had been canceled as well as how my monthly amounts over the 24 month contract had fluctuated. I received an email in return thanking me and also to provide certain details. I never heard anything back until I had to email AGAIN to find out what was happening. I then received an email and another person to deal with and got the exact same email again (asking about details,etc.).

This has just gone in circles and nothing has been done up to date. This needs to end now, and my money needs to be returned (as well as all the interest that has been made in their account from my money).