Recently moved from AT&T to T-Mobile, everything (voice, data, text) seems to be working BUT my phone boots up with an AT&T logo, there's all sorts of AT&T crapware still on the phone, and I can't seem to get the latest Android version. Also there some pesky things like the AT&T software build doesn't seem to have a Call Barring feature exposed which is not cool.
I've a Galaxy S7, firmware is G930AUCS4APK1 running Marshmallow 6.0.1 OS.
I can't be the only guy to switch carriers, from AT&T to T-Mobile, and I also can't be the only guy to move over with their S7 they got when at AT&T.
So reaching out for some guidance:
1. I'm not sure I'm getting all of my security patches anymore, or am I as the device firmware suggests its an AT&T build but I'm no longer an AT&T customer?
2. is there a standard procedure for situations like mine, which can't be unique for customers switching like I am, where I can upgrade my S7 to Nougat with proper T-Mobile firmware too? After all isn't there also a complete firmware update when Nougat is installed with T-Mobile?
many thanks for any help on this ...