Hey does anybody know if I could get a refund or if It will soon be coming out for Mac?
The page says it's only available for Windows, iOS and Android. I'm not sure how refunds work on itch, but you should always look for Mac compatibility before buying a game you plan to play on a Mac.
If you really want to play the game on your Mac, you can learn how to use WINE to run Windows applications on your Mac, or you can use Boot Camp Assistant to run Windows 10 on your Mac, and thus be able to play Among Us on your Mac.