At my waterfront on an inland Canadian lake and made a phone call to my daughter. Suddenly I had 2122.38 MB data usage spike at the same time. WHY?
My guess is that your phone didn't all of a sudden use that much data all at once. Did you receive a notification that you have used that much? Even doing system updates, 2122Mb is a lot to use in one shot. My guess is that you've used that much through your billing cycle.