I just upgraded to Iphone 6+ and it says i've used almost 12gb this month! Ive never come close to 4gb in the past? Ive tried everything recommended to stop excessive data usage, but its still eating away! I disabled a bunch of apps, I disabled "wifi assist", I restricted push notifications to email over wifi only & I disabled background refresh for 98% of apps! Not to mention, I almost never have service or reception? I am SO frustrated & am about ready to switch to T Mobile or AT&T!