How did I use all my 50gb of data on vacation?

Hi srcreate,

If you powered off the modem before leaving (unplugged the modem, switched off the power strip it is on) then when your refresh date comes around, we can't communicate with the modem to refresh the data. As soon as the modem powered back on, the data would appear. 

In your case, however, I see the modem has been powered on for quite some time. I pulled a random time frame during your vacation to take a look at and I see  a couple of things connected like a Sonos Zone Player (with attachments?) and AppleTV. Though you were not there, is it possible that anything you might have purchased/installed on another Apple device (music, movies, tv)  synced the download with the AppleTV automatically using the same iCloud account?

-Amanda