Earlier today I tried installing to the new 10.2 nightly update. I got an error and was unable to update so instead I reverted back to one of my back ups. Now I know for a fact my phone is an AT&T phone (bought it from there and the sim is from there) but now my phone gets no service and it gets read as a SGH-T999 phone. I'm not sure why and I haven't been able to find anything in terms of fixes. Help?