Syncing of things like Dropbox possibly.
I don't use drop box, and it all happened in a 90 minute period of watching a movie on the harddrive...
Had issues previously too when connecting via USB, where all the sudden 100MB would just go missing, my airtime get chowed up with USSD command to check balance refusing to work.
There would also be leftover data the next data the next day, under 10mb even though it went into OOB eating up the airtime.
But this isn't 100MB, this is 2.5Gig actually that was downloaded at hyperspeed, and I cannot figure out what it downloaded. Checked my Steam downloads, and everything was paused and the same, there isn't much.
The only reason I used Vodacom was because my CellC dropped so why didn't CellC download whatever Vodacom did? I only ever get these issues when connecting my phone via USB cable, never via wifi or the dongle.
I gonna have to request my data usage on this one, because I'm completely stumped. This feels more like a glitch than a accidental download.