Hey there, I’m sorry you’ve run into this.
Since this involves a previously redeemed product code and checking what may have happened to the entitlement on your EA Account, this is something that would need to be reviewed by the EA Help team. They have access to the account and purchase information needed to investigate whether the game can be recovered or restored.
I understand you no longer have the original receipt, but I’d still recommend contacting EA Help and providing as much information as you can, including the original game box, product code, and any other proof of ownership you still have. They’ll be able to advise what options may be available in your case.
Unfortunately, we’re not able to reset or restore redeemed product keys through the forums, but EA Help would be the right place to have this looked into.