Store refund procedures
If you need a refund for a product bought on retailer stores :
Apple :
https://support.apple.com/en-us/HT204084
Google :
https://support.google.com/googleplay/answer/2479637?hl=en
Steam :
https://store.steampowered.com/steam_refunds/
Microsoft :
https://support.microsoft.com/en-au/help/10558/microsoft-store-returning-items-bought-for-exchange-refund