ask for their phone number and then confirm their name and address. SM said she'd reprint the receipt and put it on the bulletin board in back so if the customer comes back and gives the same phone #, we'd recognize her. Of course this doesn't help if it was the friend who swiped the bills or the daughter that made the change who absent-mindedly put the money in her purse.
Dad thinks that not only did the woman making the transaction pull back the bills on purpose, he thinks she might try to return the necklace and then have another $52 (plus the 91 cents) in her wallet.