Just because you buy it somewhere else, it doesn`t means that it works on different plattforms. Windows Exclusive.
Somehow, when you posted that it said "@SimplyGaming quoted you in a post". Then I looked and you quoted the FAQ. Am I the FAQ?
XD I changed your quote and the username. Example: It's impossible to directly quote the wiki, devblog or FAQ.
Refunds can be requested here: http://store.steampowered.com/steam_refunds/?l=english Read carefully that page.