What Tesla is dealing with is way more complex than a simple supply/demand or pricing problems. Frankly, I wish Tesla management would communicate this to their employees, or even their customers, and everyone would be way more forgiving and be less in the dark.
Every quarter, Tesla has to deal with a very complex logistic problem, in a market that's extremely low margins, with an executive team that's way too optimistic on production goals -- each of the above compounds which creates this massive end of year chaos.
Logistics:
Keep in mind currently Tesla is only producing cars out of the US factories, but they have a global demand. In an ideal world, Tesla should be like Amazon and just ship the order out in the order they come in. However, Tesla cannot do that because shipping cars internationally is very expensive.
In order to keep their delivery cost down (because they are in an extremely competitive low margin market, they need to save every $), they have to bunch deliveries geographically. So this is why they usually allocate the first month of the quarter for all European deliveries, 2nd month for Asia, and third month for the US.
Low margins:
Tesla Model 3, and the soon coming Model Y, is meant for Tesla to enter the mass market -- now they are competing with BMW, Lexus/Toyota, Acura/Honda, Audi, etc, and enter a segment where margins are extremely low, and customers are extremely price sensitive and value conscious -- kind of self evident on all the complaints you see in this forum around why you have to pay for destination fees and premium connectivity.
Management team optimism:
Now, you coupled all of the above with a management team that's not seasoned Toyota executives, they are essentially still learning on the job. The most obvious mistake they made here is they factored in historical cancellation rates into their production projections.
With the tax credit ending EOY, there's an extremely low rate of cancellation. Let's be honest here, anyone can put a $100 order down, may be they should've raise that price to $1,000 so there are less people who would put an order down.
So now, you have one month (December) to deliver all the demands that accumulated from October and November, for the entire North America. With historically low cancellation rate, and a management team that thinks if they just work 24/7 around the clock (and they did), they can probably make sure everyone gets their car. If everyone goes perfectly, they probably could've, but we all know nothing ever goes as planned.
Tesla is not intentionally trying to screw up your order -- please at least take a moment and think about the challenges they are dealing with. Frankly, I'd hate to be Elon because this is a very very tough business problem to solve.