Unauthorised debit order and Overcharged contract

I've had such a terrible service and experience with MTN. In January I complaint about the debit orders that went off my account for 2 consecutive months after cancelling my insurance on the 2nd of Dec 2019 and still, l have not been assisted. They claim that they cannot find my cancellation call recordings. On 15th January I changed my cellphone contracts which could cost me R388 (R200 for 20GB night, 20GB day + R29 Router) and R220 for my MTNchoice flexi airtime at R159) with no cellphone device but they debit an amount of R492.90 from my account since February to current and I am not sure of what else am I paying for because this is not what I signed for. From January to April I’ve been given so many reference numbers for MTN for the two queries but no one is helping me. Instead I’m being taken from pillar to post and no one ever gets back to me. I deeply regret my decision to upgrade my contract with them and I so wish MTN could tell me that they have cancelled all the contract I have with them, so I can look for other BETTER service providers. I moved from 600mb to 2gb (that would last me for a month) to 20GB and I tell you that their 20GB is the new 600MB. It’s TERRIBLE!!!.

Can someone also please assist me with contact details of where I can escalate this matter to. I’m so disgusted by MTN