delliberately ignoring my requist

I have phoned the call centre more then 15 times requesting a manager to adhere to my request. I am due for an upgrade but Cell C offers me a better package and Vodacom promised to look if they can try to match or come close to the same package. Bongani, Vigil and Presley whose names i can remember said they will come back within 24 hrs but not one of them even rep**** to my e mails. I am supposed to be a special Red Tag customer but even the fact that I've had this number for more then 20 yrs they treat me like a Pre-paid customer.