Security System or Key Fob Issue??

[T-Indy]

Dropped my 2008 QX56 off with a parking service at the airport. When I got back they can't get it started. Turns over, but not getting gas/spark. I think it is security related to the immobilizer system. Tried to start using hard key, but had no luck. Dealership says maybe key fob got deprogrammed. Replaced battery in fob. Still no luck. Second key fob seems to be hiding from us. Any other ideas to reset the system?