I’m not sure if this is the latest scam or not but it points out the value of a good return policy.
Your online store ships an item to a buyer using a credit card. A little while later, a lady calls up -your store-, hysterical, that someone stole her credit card and recently made a purchase. She asks if you could resolve it by refunding her money. Hopefully you do not.
First of all, if a credit card is stolen or misused, the correct place to call is the credit card company, not a store. Besides, how did the person know so quickly that a purchase was made? If you are like most people, you do not check your credit card purchases online every day. With the credit card company the buyer can dispute the purchase in which case the credit card company gets in touch with the vendor (your store).
One wise person has a return policy that no money is refunded unless they are contacted by the credit card company or the merchandise is returned. Crooks will back off contacting the credit card company. Of course, the credit card company may trump you and decide to issue a refund.
Regarding the original story, in case the item was shipped, you can try to stop the shipment or redirect it back to you if there is enough time. Contacting the police may help but I doubt they will break down the door and recover your merchandise.