The arrogance is always a bit baffling. Yes, you, average Joe, with your level 120 iLvl 432 DK-Main are most certainly able to sue Activision-Blizzard, a multi-billion dollar company on basis of "They moved the release date."... Not to say that its not right to fight large companies? ... But do you really believe that they are not quadrouple secured in their EULA about those things?
...even if they had not offered refunds on their own.