Sympathize with your frustration. I went through a similar situation. While there is no excuse for the lack of communication from the dealer, there are things that affect production (in my case, it was a port fire where they loaded the cars on to the ship). Like you I ended up buying at a dealership that I would have avoided had I known more about them before, and the only updates I got were when I could catch them myself on the phone. However, at the end of the deal, I got the brand new car I wanted, made exactly the way I wanted, with nobody else having driven it, etc. The cars come filled with oil, etc. so you don't have to worry about that.
Just be sure to do a thorough walk around on the car when you pick it up so you're comfortable with the condition before you pay and leave. Once you give them the big check, their incentive to make you happy really diminishes.
Hopefully you'll be driving the car in just a short period of time and this will all be just a memory... good luck!