Hi. Following my upgrade for my son... we keep on getting charged for mobile data usage even when connected to an internet source. Some months its as much as £50 more. Tried speaking to customer service who say that's normal. Customer service on Twitter say it's not right but can't seem to get a clear answer. On his old phone this was not an issue it seems ridiculous as I'm on EE and it doesn't affect my bill in any way. Can anyone help please?
Install the "My Account" app on his phone and check data useage in the app. After this depending on what device he is using look at the settings and check for data usage. There will be guides out there for how to do this on IOS or Android so find out what phone then have a look for a how to.
It should break down data usage for wifi THEN mobile data and once you're looking at mobile data it should tell you what app is using the data.