I feel your pain, buddy. Crap like that is exactly why I let my FFL expire 1 year and 1 month ago and I haven't regretted it once. NOT ONCE!
I waited 3 months for a DPMS upper (nothing fancy, just a standard match upper).
I waited 2 months for a RRA upper.
I waited almost a year!! for a DPMS rifle.
I got tired of the FedEx guy ringing the doorbell and sprinting back to his truck before I could get to the door. They must get a bonus for missed deliveries or something.
The last pistol I ordered as a licensed dealer sat at a UPS hub for 3 days (weekdays). Just SAT there. No apology, no excuse, no refund of the "Next Day Air" that they started charging when the UPS terminal workers stole so many handguns that their insurance company hollered calfrope.
I got tired of the gun manufacturers publicizing the new "wonder gun of the year" then actually having it at the wholesalers a year later. Had to answer 500 phone calls about the wonder gun in the meantime.
I got frustrated at having to call half a dozen wholesalers to find a SIG P226, a Glock 17, or a Marlin .17HRM rifle in stock.
QUIT! Tell UPS and FEDEX to go screw themselves!! I am 100% happier just going to the local gunshop when I want something, and I bet you would be too. I didn't sell guns for a living, just as a hobby and to give the members of our local shooting club a break on reloading stuff, competition accessories, etc. and maybe that is why it was easy for me to quit.
Maybe you ought to try it!