vodacom data disappearing daily

<p>On the morning of the 27th of September i bought 2GB of data. The same evening all the data was gone! I sent a few emails and that was it! No updates or downloads took place during the day. I again bought 2GB of data on the 29th of September (midday). I worked on emails only and withing a few hours the data was again all gone!! No updates went through. How is this possible? Please ask someone senior to contact me urgently. </p>