No feedback from MTN

I have request 3 times an itemised billing and details of the data on abovementioned number.<br> <br> 7/1/2016 - ref 141 264 231<br> 14/1/2016 - ref 141 648 084<br> 19/1/2016 - ref 141 879 337 <br> <br> All 3 times I was informed that the information will be send to me within 2 to 24 hours. Up to 25/1/2016 I have not receive anything from MTN.<br> <br> I am receiving 1 gig data every 7 th of every month. I am using this number for Facebook and whatsapp's. On the 12 - 15 th of each month, I still have more than a gig data left. Next morning I get a sms saying your data is depleted. Once, I checked my data in the evening - I still had 1.78 gigs of data - next morning 0.<br> <br> I am trying to investigate this matter, but how can I? None of my requests was adhere to.<br>