Everyone loses receipts. How about an automated system for stores that tracks receipts and item purchases so that people can return them without having to have a physical receipt, like a million stores currently require?
Hey!
I think you should dive deeper. Since stores would be the one buying this, why would a store spend money on it? It sounds like this might actually COST them money (people are able to return more things), not actually make them money. Would the increase in reputation be worth it?
Indie Hackers won't be able to answer these questions, you should talk to store owners. about it. If you need help reaching them, I have a short blog post on how to find channels that work for this type of exploration here.
Best of luck!