so let me see if I have this right, you bought a new RV and found out there is a leak. the dealer wants to fix it (I am assuming under warenty as it is only 5 weeks old) why would you even request a new RV when they are going to fix it? I would have hung up also but I would have been rolling on the floor laughing first.. it has a leak and they are stepping up to fix it and it will be better than when you bought it. the manufacture isn't going to do anything for this aside from authorize the repair which they probably have already done.
you want advice, let them fix it and then enjoy your trailer