Accidentally refunded a customer before they’ve returned the item. Where do I stand?

Long story short, we received two refund requests of similar products last week due to the customer no longer requiring the item.

Amazon automatically refunded one of them that we received back, and I thought it had been missed on another and refunded the other customer manually.

Now I’m not sure if the customer will return the item but it’s a product we sell a lot of but are hard to re-stock.

Where do I stand with this? Would there be a way of getting the money back until the customer sends it back? Or is this something we’ll just have to cut our losses with?