Recently, I noticed large data charges after spending hours on Facetime (iPhone 6, AT&T) for business. Turns out I was connected to wifi (showing three bars), but Facetime was using data anyway. I realized this by going to cellular data and turning off Facetime, prompting the call to end immediately. I'm wondering if anyone else has this issue; also, if there is any way to correct this besides turning off data for the Facetime app. Seems to me like it's either a glitch causing Facetime to not recognize the wifi, or a conspiracy by AT&T to make me pay them even more money for these outrageous data overages.