Expired Food
Sorry, if you find something in the back of your pantry that you simply forgot that you’d brought, there’s no way Costco will take it back. They can’t re-sell expired food, so the best thing you can do is simply throw it away.
Hey, perhaps now is a good time to clear the rest of your pantry out to make sure nothing else has expired. Clear some space and re-stock where you have to- just make sure not to buy in bulk again!