Usage depleted overnight. All updates set during free time.

UGGH!!!  I haven't been on complaining in awhile because everything went back to normal.  2 Iphones connected to wifi when home and our normal computer usage.  Both phones left home this morning and all computers turned off.  All updates stopped unless I check for them manually.  My allowance refilled this morning. I came home and turned on my computer and my data was at 39%.  Turned wifi off my phone and it was dropping while I was sitting at my desk doing nothing on the computer!!! Its went from 39 to 25%.  I signed in to write this and have dropped to 20%!!!