Received a data useage notice that my account was at 9 gigs of useage last month! We only use total of 1 to 3g per month. I was alarmed but immediately switched bill to unlimited. The next day, the bill report .7 gig of data use. Called Xfinity and rep told me I had to call back the next day because he couldnt verify the data. So I went online and changed billing back to by the gig. Got bill and I was charged by the gig - for 9 gigs. Has anyone had this happen? Appalling. How can I trust Xfinity? I am about to install Home security. Maybe I shouldnt if they cant handle simple billings correctly.
Look in the settings for mobile data in each phone. It'll show which apps are using mobile data, and how much each is using.