Last week I bought a few things at Wal-Mart, paid with a check. The young kid at the cash register did his thing, put the check in the machine, wait for the slip to be printed, etc.... then he said thank you, have a good day and gave me my check back.... bwaaaah... I said, Hey, you should keep it, give me the sale slip instead
A few times I paid something with a $10 bill and the kid at the register gave me change for $20.... I did bring it to her attention.