All authorized Gem orders must be done within the game and processed via iTunes or the Play Store.
It is possible that several third party websites or services are claiming to offer in-game currency for Nonstop Knight. However, none of those are safe to use and are authorised by or affiliated to flaregames. Such services or sites might even ask you for your iCloud ID, your Google Account details or other log-in credentials. Never give out your information to anyone but official flaregames Customer Support representatives. Otherwise, unauthorised persons are able to log in to your game and your account's security is in jeopardy.
Please understand that we are unfortunately not able to assist you with Gem purchases done via third party websites or services.