Frustration of closing an account at MTN

After closing the MTN account the Debit Order keeps going through. I have phoned MTN on numerous occasions, and every time I get palmed off to someone else. I then sent them an email, where they responded by email and said they will come back to me within x amount of hours - nobody every did. I then finally managed to get someone at MTN to respond to my email - this person then sent the email to someone else in MTN, hoping for some sort of help, and so the backwards and forwards of emails continued. Nobody is willing/capable of stopping the Debit Order? This all started in the beginning of November 2017 and we are currently in March 2018. Will they be refunding the money?