Diablo IV purchased in Amazon, redeemed but could not download from either the store and...

My name is Fernando I'm an independent consultant, I'm happy to help

Is the game you bought physical or digital media? It may be that it came from a different region than yours, contact the dealer to report the incident.

Hope I helped and see you soon

you bought a code from amazon when redeemed on your microsoft account will always be present on that account, go to your download or purchase history either in the windows store or the xbox app and you will see it available. its the same for all games.

you can find flight sim either in the purchase history, download history or in the xbox app in your library, failing that load the store and search flight sim and should say owned and you can download it.

but you must be signed in with the exact account that was used when you redeemed the code from amazon.

You mention it was paid for with store credit from Amazon. Was the game purchased via Amazon? That is to say did you get a redeem code from Amazon that you entered into the Xbox Store? Or did you an Xbox currency/gift card that you then redeemed for value
on the Xbox Store?

Could you please instead pre-ordsr the game here using your account? https://www.xbox.com/games/store/diablo-iv-stan...

Once you successfully pre-ordered it, try downloading or accessing the game again. Be sure to restart your console.

Well with xbox store you get the download immediately

With ms store and amazon or cdkeys you either get a prepaid code or a disk

A prepaid code you would still have to redeem it on an xbox store