Pathetic Service from Operations Manager MTN SA CCI SA

Hi, I have been with MTN for past 15 years, and I must truelly say that the service from MTN CCI SA, is pathetic, I have Done a Data Sim Contract, with the Assurance from the Operational Manager, that I would not have a problem with my Data, As I would br given my full Allocation of Data 50 Gig Day and 30 Gig Night Data, . I have informed him that I have not being given my Full Allocation, as I'm only Getting 20 Gig Day and 15 Gig Night Data. I have called the Operations Manager at CCI SA number of times and sent Emails, but have not received and correspondence. When I call the Call Centre, and ask for him, I am told that he would return my calls, I am getting charged the full amount for contract but getting ****** from MTNSA. If the Operation Manager can treat customers in such a way, That's the reason the service is pathetic.