Zamboni - I think your angst is well understandable. Dealers who cannot and do not keep their customers happy - well, at least informed - are harming their reputation and so potentially also their business as a whole.
I am no dealer of course but - I think I would try and keep a calendar or journal - with ''expected'' dates for incoming guns - that way a call to customer could be made to keep them up to speed if delays.
All too often it seems, due dates are over optimistic - maybe to ensure getting orders. That is counter-productive IMO if in the end it seems they were transparently wrong. Those things called trust, respect, loyalty and integrity are for me, integral parts of a good business - shown/earned in many ways but including keeping customers up to speed and returning calls etc.
I just hope this will resolve, satisfactorily in the end - you with the gun you want and not out of pocket. I could have sold one of my pups a few times over already I think but - hope to try and keep both a good while yet.