Same here. I got my tablet back today. I turned it on, connected to wifi and it prompted me to update. I did. Wifi, not Kies. Same problem. It won't shut down. I will contact Samsung again tomorrow.
So I got my tablet today and I turned it on to see that it had android software 4.1.1. Then the software update icon popped up and I updated to 4.2.2. Then the same problem happened again like the last time. The tablet wouldn't turn off and it would automatically restart. I contacted Samsung Support again and they had me do a factory reset which then fried my tablet again. It doesn't turn on. So now I have to send it back again for a 2nd time. This time they said they may have to replace the tablet either with the same tablet or a different model tablet. But I stressed to them to make sure to update the tablet this time to 4.2.2 so they can see the problem I'm facing. We shall see next week I guess what happens.