This guy comes into my store and does this all the time.  Never buys anything, just plays an ex

This guy comes into my store and does this all the time.  Never buys anything, just plays an extended game of Telephone with gift cards.  My co-workers theorize that he’s using the receipts to commit tax fraud, but we’re not 100% sure.  Would anyone reading this have any clue?  Have you guys ever encountered something like this, and is it for felonious reasons or not?