I agree! I'm confident that between 'Fantastic' and 'Airstream' they will get you taken care of.
However, if I were you, I would remember this situation when it comes time to buy a new trailer. I just feel any dealership that can't (won't) remedy such a minor problem for someone who just purchased a high-ticket item, such as a new Airstream, certainly deserves no confidence when it comes to servicing/correcting anything major that may occur.
My reaction would be to bypass this facility for any future purchases.
But, that's just me.
I'm sure you will get the problem resolved by dealing directly with 'Airstream' & 'Fantastic'. You simply shouldn't have to.