MTN - No service at all

I entered into a two year contract for unlimited LTE data with MTN. This contract expires on 26th October 2023 and I do not wish to continue with it as the service is so poor. I cannot phone their call centre as I do not have access to the free call option and it costs me too much money to hold on for 30 to 45 minutes waiting for an answer only to be cut off on transfer. I have therefore been emailing them. I have sent at least six emails, one of which was answered with a request for my details. I rep**** promptly but have heard nothing further. More emails and no further communication whatsoever. If I cancel my debit order from my side, I have to do so each month. This costs me money at the bank and I am sure it will affect my credit rating. WHAT DO I DO!!!!!! This company deserves to be fined for poor service.