Steam has a refund policy that require you to have the game less than 2 weeks and played less than 2 hours otherwise you can not get a refund.
I knew where I got myself into by buying an early access game. Some people apparently anticipated this game as the next coming of Jesus Christ and then get disappointed because the controls are not to their liking and the invert mouse option is not there, better refund it quickly before i play more than 2 hours. GTFO ?