Hey Ryan!
Nice to meet you! I'm Darhyl, an Independent Advisor. I'm sorry you are experiencing this on Minecraft coins. No worries, let me help you sort this out.
It is possible that the Minecraft coins was redeemed on a different account.
To confirm this, kindly sign into your Microsoft account on account.microsoft.com > go to Payment and Billing > then Order History.
From there, check if your Minecraft coins were redeemed there. If you have found the codes transaction, use the same account to login to Minecraft launcher.
If the codes transaction wasn't there, check your other Microsoft email accounts under Order History to locate the Minecraft coins.
Please take your time and let me know the results once you're done.
Best regards,
Darhyl