Well you need to do a compression test first and get a definate answer whats wrong.

If its a piston then thats not easily fixed short of a re-build

I duno you could ring jamsport but i dont think they will really do a lot? Did you turn the boost up past the level they recommended when it was set up?

I expect they will say if the bleed valve has blown off then its not covered by any guarantee u may have had on the work?