Thing is, BF4 seems more like a personal preference than "unplayable" surely...have you been able to play? If yes, then not sure any amount of badgering will get a refund ...
I was able to play Singleplayer reasonably well, but multiplayer still runs bad and has a terrible delay. Besides I was complaining more about the new need for speed which runs even worse and is terribly optimized, its giving me 20fps yet my GPU isn't even averaging 50% usage. And then the game will crash -.-
I'm not sure whether this problem is to do with their engine (Frostbite 3) or the publisher, EA.