Please cancel my contract and refund me

I have sent an email to MTN at the end of July to cancel one if my accounts with them. I have received an automated reply that I will be contacted between 24 to 48 hours. I have sent a 2nd and a 3rd email ans I am stil waiting for somebody to call. It's no use trying to call the customer care line, because you only get a robot voice and there is no ootion to speak to a person. The account still has not been closed and I have been billed at theend of September and I have noticed on my October bill that I have been charged again. It is realky frustrating to try abd contact companies where there are no human interaction or they make it extremely difficult to get hold of a person and not a tin voice.