Front strut mount bad since build date. Need Chevy Customer Assistance... help

Did GM use faulty strut mounts until the later 2012's were built? Why were these not recalled? I just went to the dealer to have my toe-in set (I believe, I've read that is the only adjustment possible?) after buying new tires after having a blowout on my strut defect wheel. The service tech showed me a 1" or more movement at the top mount of my passenger strut; the whole strut assembly was fine and intact other than that! My warranty has run out but my volt must have been built this way or the nuts not tightened enough or an improperly designed bushing has caused this defect. I have opened a case for a senior advisor to decide but GM tells me TSB's are not covered since my warranty has expired! There is another strut available for serial #'s after mine, I cannot get the TSB from them: so how can I fix my car with no real schematics shown on the parts catalog showing the differences. Dealer wants nearly $800 bucks to put new ones in but the only reason it wasn't done under warranty is because myself and my wife both wear 2 hearing aids and never noticed the clunking.