Dear Microsoft Customer,
Thanks for purchasing an Xbox game from Microsoft store.
When you bought your game, you were entitled to a promo code good for $10 off your next order, but there was a problem with those codes. Now that we have fixed it, we want to make sure you get your $10 discount.
Here is all you need to do: Come back to Microsoft Store and shop for what you want. At checkout, use promo code (I DID NOT DELETE THIS PART HERE, Yes! it's empty in first place). Your $10 credit will appear before you complete your purchase.
Thanks for shopping at Microsoft store.
The Microsoft store team
You will find that Microsoft send you email NEXT DAY WITH A NEW CODE
what I'm saying here is that for people used their code ALREADY without problem
I think Microsoft "accidentally" send code AGAIN (TO EVERYONE WHO USED CODE)
no matter the code is valid or not
MIGHT BE YMMV AS WELL