Good to hear they didnt brush you off, some dealers do that so they dont have to deal with it. Dont ask me why ,but if i was a dealer I would try to be as helpful as i could trying to reach "customer satisfaction".
Good for you man on holding them to what they are suppose to do anyhow!
when you get that new part,even if they put it in for you, take it home and then remove the cluster again and put some clear silicone caulking around every area where it looks like condensation can enter the cluster. This helped keep my Ford Mustang headlights from doing the same thing.
Good luck
"chubbs"