In-app purchase request lost...

My son made an in-app purchase but the request was lost. The app shows a grayed out button saying the request is still pending. SInce there appears to be no way to contact the developer we dont know how to reset the request so we can try again. Great Game... just need a little help here.

ThatsNotWhereIWantToGo about Clash Royale, v1.8.1