A) You didn't pay for early access. You didn't pay
any extra for your early time into the game, you pay the same amount as other people will when they purchase the game with
no early access - therefore you did not pay for any "early access."
B.) You were never guaranteed an amount of early access per se....you paid for the game and were granted early access starting at a certain date.
Nowhere were you guaranteed "3 uninterrupted days of play time" (or 5) but instead: "We will grant you access 3-5 days early" -
every single game with an online element allows for changes and updates during that time.....there is no denying this - its in the EULA that you agreed to.

As someone who has been playing MMOs since 1999, I can guarantee you this launch has been the smoothest, lowest downtime, least amount of bugs I've ever seen in an MMO launch. If you disagree with this, you haven't been present at very many MMO launches (like, none) or you just need to calm down for 4 hours and get some perspective on life and then everything will be fine when the servers open up again.
C) What would you have them do? Did you imagine a perfect game without bugs? So they have 2 options: take down the servers to patch them, or leave them up with bugs. If there were bugs, you would complain about the bugs, if there was fixing happening, you complain about that.
D) Every game like this has to have some mandatory downtime before the game goes live the next day to link up the online store (where you purchase account time etc.) with the game servers - this is ignorance on your part and not incompetence on theirs.
E) Just calm down, the game will be live again in a little while and life will be good again.
I know some will disagree with what I've said here - but I want to say that after playing MMOs for 15 years, this is the most I've ever enjoyed one, this is the place that I will be hanging my hat for
decades to come and I hope you will to. The devs are hard at work doing what they do best, and trust me, they want this game to succeed as much as I and you do, they aren't doing anything that would intentionally or unintentionally make themselves "look bad."
Thank-you ESO devs, and my wife and I will send you flowers soon.