We used to get this error, cause our products are set up in Monetization/In-App Purchases section, specifically non-consumable. We then switched to set up products in Monetization/Subscriptions: Non-Renewing Subscriptions. We no more got errors about: An In-App Purchase has been returned. Hope this could help someone in the future. Best luck in building your dream chaps!
Topic:
App & System Services
SubTopic:
StoreKit
Tags: