Persistence is the key. You have to be the guy making all of the phone calls -- don't wait on them to call someone and get back you because they won't do it. Call them daily while being polite. If they need parts, make sure they actually order them (I've waited months with my dealer to find out they never ordered them).
You are your own expediter. You are your own link between the dealer and the manufacturer. If you rely on one of them to step up and do it, then it won't get done quickly if at all.
This RV world is not like a normal customer/service relationship. You have to do all the nagging, calling, follow up, etc.