Chevy Cobalts Key Stuck In The Ignition

Hello,Chevy owners of the Cobalts,Malibu,Impala etc please help.
When the battery of your Chevy completely dies for some reason does the key get stuck in the ignition? The Chevy dealership told me that that all these Chevys are designed that way. I think it's not true because the battery has died before on mine and the key never got stuck in the ignition.
Ok,so here's what happened,last month i had the entire ignition switch on my 2006 Chevy Cobalt replaced because of the massive recall. I never had any issues with it whatsoever before but i just did it as a safety precaution in case it ever happened in the future.
Last night the car completely died.No power at all.Whenever I turned the ignition switch it would move but no power at all,no lights on the dash,nothing. I blame it on the ignition switch. The dealer tested it and said it's the battery. They charged me for diagnostics and everything,towing etc. Since I bought the battery from Advance Auto Parts and it is still under warranty i took it there. They tested it and found that the battery is ok,Nothing wrong with it. What should I do now?. The dealer doesn't seem to want to accept blame for what i think is the ignition switch.