Mine would not update either because I was not using an at&t sim card for my 4g/lte and I was only using wifi.
I tried Samsung kies, that did not show kit kat upgrade for my tablet.
I called at&t... they said the only way to get the update is through their servers. In order to do that, you have to have an active at&t sim card in the tablet. I tried the at&t sim card from my galaxy note 3 - I was able to get a 4g/lte data connection, but I could not update the tablet.
So, I went to at&t and got a new sim card and reactivated my data plan for the tablet. I then checked for updates and it updated immediately.
Last edited by dandroid7; 31st October 2014 at 07:43 PM.