MTN *****ing money out my acc after contracts cancelled.

I HAVE BEEN STRUGGLING TO GET MY 2 MTN contracts cancelled as they reached term April 2020. I have tried phoning relentlessly yo cancel my contracts. The 083 135 service was not able to assist me in fact the call just dropped. I tried emailing them multiple times and eventually 5 July it was confirmed by MTN per email my contracts have been cancelled. End of June 2020 my one conrract was debited and I thought probably some notice period. Yet end of July they debit both accounts!!! I am fed up. They are literally *****ing my money and if I reject the debit order will face bad credit score. I have emailed them again on the 01 Aug 2020 and to today no response. All I can say is never ever sign a contract with them.