The disappearance of airtime, continued

So, once again, my airtime disappeared. R200 was loaded on 27th September, and by 29th it was gone. Last time it happened, MTN's excuse was that it was data. This time around, though, I have a valid reason why my airtime can't have been depleted by data usage: I USE WIFI. So I wonder how MTN will explain this to me. I am getting seriously p.issed because this is not the first, not the second but the THIRD time it has happened! And each time it just a polite : our system shows that it was data usage. Bull. Your system is drunk and should be sent home to recuperate. This time I didn't bother calling the 808 number because all they can tell me is what they see on the system. They just work there. <br> <br> I would like someone to explain, not just give me a bull excuse, but actually explain how R200 airtime (not to mention the R149 airtime from the previous month) can disappear in two days while I'm using wifi (at work and at home, mind you) and while I am not registered for any content services (first thing I checked as that is usually the second excuse) <br> <br> If this is not resolved I will be very upset. The third time. THREE TIMES.