Deduction of airtime instead of data bundle

At around 12pm I purchased R30 airtime and I still had data, at 6:48pm I received a message saying that I am depleting data at out of bundle rates. I checked my balance which stated that I had 42.01 megabytes of data left and no airtime.<br> <br> I called 173 at 6:53pm and was informed to call back in an hour, during this time I used up the data I had left and only purchased another 1gig of data at around 7:23pm. I called 173 again at 7:58pm and according to the system I had no data bundle when I loaded the airtime which is why it used my airtime. <br> <br> I asked the consultant to tell me exactly when my data bundle finished because I was using WhatsApp during the morning before I even loaded the airtime and somehow after the airtime was depleted I could stay connected to the internet, go onto Facebook, scroll through images and even download images.<br> <br> When I asked how is that possible if I didn't have a data bundle I was told it reflects on the system that I only loaded data at 7:23pm. <br> <br> How doesn't my data bundle show and how can the system not explain how I was connected to the internet?<br> Mtn is taking me for a ride because it is not the first time this has happened.