Sorry to hear that you are having trouble with this situation. Could you please first confirm whether the purchase appears under the Microsoft account you are currently using to play the game here?
https://account.microsoft.com/billing/orders
If the purchase appears in this account, please make sure that the same Microsoft account is currently signed in to the Microsoft Store app.
If the purchase does not appear in the order history, it may mean that the game was purchased using a different Microsoft account, or that you previously accessed the game through Xbox Game Pass instead of purchasing it directly.
Please let me know what you find.