My son had tmobile service with his iPhone 4s for the past 8 months and the usage never went above 50-60% of his 1GB plan in any one month. Due to coverage issues in our area (hilly), I had to switch his line to AT&T and for a new iphone 5s on contract.
Starting the very next month, data usage exceeded the 1GB max and AT&T automatically charged me $20. Unfortunately I missed the email/text about 75% data usage. Since then, every month, upon getting the email from AT&T at 75% usage, I'm forced to turn off his data and it is frustrating.
He has not changed any of his apps usage patterns (Facebook messenger, Snapchat) which he used while on the tmobile network. He is very responsible and tries not to use snapchat etc on the LTE network.
Another problem is that when I switch off data, sending and receiving text (even if iMessage is turned off) does not work either.
When I checked the history of his data usage, large chunks of data is getting sent out/in at odd hours of the day and night when I know he was on Wifi (at home and at his school).
Turned off the following:
-Diagnostics
-Location services
-Notifications
-iMessage
I've seen hundreds of such complaints on this forum but never saw a resolution. Is AT&T addressing this problem and providing tools to diagnose it or are they turning a deaf ear? Maybe it is time for me to switch back to Tmobile.