my galaxy note 8 tab model SGH-I467 4.1.2 ANDROID NOT UPDATING

[AC Question]

the model of my galaxy note 8 tab is SGH-I467. as far as I can tell from my research this model came out with android 4.1.2 jelly bean, which is what this tab is at currently. looks like it has never been updated. it looks like it is branded to at&t so I was thinking that maybe they had it locked out somehow. do you think that it would be possible to get an unlock code from at&t and unlock it and maybe it will then upgrade? I know that people get branded phones unlocked after there contract is up. any help would be greatly appreciated.