It's what you do in the phone, not how much you are on it. A daughter constantly texting will use very little data. A son Watching a few episodes PewDiePie or something similar will quickly use up gigabytes of data. To the kid, they are not doing much. It is interesting but it is usually a kid causing the overages (not always). The vast majority of the posts claiming impossible data use is actually users using the data. A few are caused by the phone in some type of data loop, trying to download an email over and over, or a stuck app, or wifi turning off when user is not expecting. it is amusing when someone says it is impossible to use 2 gigabytes when in fact it takes very little effort at all. Very few do basic steps to figure it out.
Also lso keep in mind the 100s of users on the forum is a concentration of users having a problem. In reality 100s of users out of tens of millions in not even a statistical blip.
Please read previous post. The solution depends on the diagnosis.
If your son's iphone is using much more than 2 GBS of data a month (from your post it seems he is over 4 gbs), it may be his use while away from home, or the phone itself.
In some cases the phone is faulty. This is a problem know to the iphone. Restoring the phone to factory and setting up as new often repair the problem.
best solution is to reset to factory and add nothing to the phone. Reset your sons Apple ID password and make sure he knows not to share it. Rather than restore his information, add it back manually.
changing settings on the phone can help.
open settings. Select cellular data. Scroll down to see which apps are using cellular. (Vital information!)
switch all high use and non essential apps to OFF.
social media apps have settings within the app to restrict video and pictures to wifi only.
youtube also has these settings.
once all restrictions are set to wifi, if his phone still has cellular use on these apps, something is very wrong with the phone.
I Haven't suggested switching SIM cards, but it might be worth trying.
PPPlease feel free to ask more questions and report any of your results.
Start a new topic or ask questions in the open forum.
