MTN is another example of poor leadership based upon quotas

I unfortunately had an issue with my Cheque account where my debits for two months (Jan and Feb 2024) did not go off my account. i was unaware of this as all my other debits had gone through. It was only when my line was suspended in March 2024 that i realised that my services (wifi connection) was suspended. I called MTN, made the arrear payment but was told that my line cannot be reinstated as my contract came to an end the promo i was receiving for the previous 24 months has ended and that I need to pay the full 'normal' contract amount. Mind you the jump went from +- R350.00 per month to a whopping R1900.00 (One thousand nine hundred rand). I refused to accept this new rates and argued that no-one from MTN sought my permission to increase my tariff without first seeking my consent. i logged calls and made follow-ups. Now MTN does not want to respond to my last call logged nor do they want to cancel my contract. I am so lost,,, social media - please help me. Ref No.: REQ***. My MTN number - ***