When in the office I am connected to the wifi, the phone is used mainly for the e-mails, I started connecting it to the wifi at work because it was using all my mobile data (not sure what I was doing when I first got the phone because it was a lot higher). The phone doesn't show me using that much but it has to be if I was firstly charged for using a lot and secondly for the internet usage to be higher at work when I'm connected. I know the simple reason you may come up with is to stop connecting but I want to understand why it's doing this and if anyone else has the same problem. I am now currently paying for a booster every month for the internet that I didn't think I originally needed. My previous phones I have never gone near my mobile data limit.