It sounds like a factory defect to me. I'm not a mechanic, but I think the problem is in the steering column. It sounds like the key reader is not reading the chip in the key properly. I think this thing is called SKEEM, but can't be positive. You really need to contact one of the Chevrolet Customer Service people that are all over this board and see if you can get some help. I'd be very pissed off too.
The only difference between stupidity and genius is that genius has its limits. Albert Einstein