MTN *****ing money

I took an online contract in August. They sent me wrong phone. It was collected and promised the correct one. After many attempts to contact them I finally got to know their consultant made an error to which I never received the phone. Again many attempts were made to contact them I kept getting transfered from person to another with still no answers. Numerous emails were sent to cancel this contract as I wasn't going to pay for something I don't have. Every single month till now they have been debiting my account. Every attempt goes on deaf ears! I'm so fed up of them *****ing my money.