I have many users complaining they purchase our consumable In-App purchase on out iOS app but it does not work. they are billed so the payment has gone through but the function in the app that is suppose to be enabled does not enable, I then tell the user to try it again and the second time they purchase this it works and the features are then enabled. The user then needs to reach out to Apple for a refund of the duplicate purchase. I am not a programmer but have had many programmers look at this and there seems to be no issue with the app so I am thinking this is an issue on Apples end. Wondering if anyone else has had similar experience?

I can't find the iPhone design template? There use to be iPhone with a cut out screen to use for promotional graphics. anyone know where this might be?