Telkom - data ********??

bought 2gigs of prepaid data and a week later it was gone. I switch my data off at night so only God knows how this data was depleted. I realised I downloaded a few songs so okay. This evening I bought another gig of data at 21.20 and an hour and 20 minutes later I received a message telling me that I have 499 mb of data left. How was this even possible when I was on watsapp and they claim to give you 500mb of free social media data. Also I was watching movies more that I was online. I tried calling 4 times to the call centre and all 4 times my calls were dropped while wAiting for an agent to come to the phone. As I type this, I am informed that I now have 98 mb of data left. HOW??