World War Z is currently available to be had for free at the Epic Games Store for a limited time only. Other games that are free at the moment include Drawful 2, Figment, and Tormentor x Punisher. If you paid full price for World War Z after February 13, 11:00 AM ET, then you can expect an automatic refund coming your way soon.
https://www.notebookcheck.net/World-War-Z-free-until-April-2-on-the-Epic-Games-Store-refunds-being-issued-for-those-who-bought-the-game-after-February-13.459311.0.html