MTN is poor in customer service

I have been calling MTN since January 2021 and 4 months later I'm still waiting for a response on all of the numerous reference numbers given and yet I'm being billed. Was called several times to upgrade my contract and when I wanted to cancel it was told that it's impossible. No one informed me that I was going to start being Bill R2000 per month from paying R370 per month. On the first 3 phone calls I made to 135 with an intention of canceling the month to month contract, I was informed that the R2000 was an error and would be corrected. Every call, email an tweet I sent/made I was told about an escalation being made but till date there hadn't been a single respond though the bill keeps increasing R2000 every month. MTN has disappointed me big time after having used the network for almost 11 years now. Their customer service has grown poor though they are quick to bill. On top of everything they are claiming that I haven't been paying my bills since May 2020 though I have submitted the proof of payments of which they later blamed some system migration. MTN is poor in customer service