Such bad service /no service

MBD inundates me with calls, about a cell C account, I dont have any other account other than my own. When I ask them to send me the phone number that is linked to this outstanding balance, they can't. I eventually paid the amount to get them off my back and now they are on it again. Sending me sms's to pay but no amount with the message. Please MBD get your information together and send emails so the clients can go to the appropriate companies to inquire!!!!