If you recently purchased the game via Steam, Daybreak Game Company recommends using the refund process. If you're unable to get a refund, you will get the H1Z1 Appreciation Pack:
To thank all of our loyal players who helped make awesome, game-changing decisions during our time in Early Access, we'll be rewarding everyone who already purchased the game with the “H1Z1 Appreciation Pack”, containing the following items:
Gasrunner Hoodie Bloom Survivor T-Shirt Splinter Camo ARV 10 Victory Crates 10,000 Skulls