Well I can't blame you for getting rid of your chally. I would have done the same. It was obviously down on quite a bit of power and I think it would be a long and frustrating battle to find where the problem lies. Regardless of what anybody may say I don't think there is a dealer around who would spend more than 5 minutes hearing you out before dismissing your plight & when it comes to warranty and dealing with/talking performance- they are polar opposites. Throwing money at the car to correct something that should never have been a problem is just pissing into the wind as well.
You bought the car expecting it to perform and it fell significantly short= unacceptable- End of story.
Hopefully the next one's on par.