New answers tagged att
Go to Settings > Apps > swipe right to "All" > click the menu button of 3 vertical dots > click on "Reset app preferences".
After my Galaxy Note 3 got all messed up by Lollipop update, I rooted by phone and installed DisableService app from Play Store. Using DisableService, you can disable AT&T Software update service. Good luck.
I haven't tried this, but in your APN settings there's a setting called "fota," which stands for "firmware over the air." Removing that APN type and rebooting your device could stop those updates.
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