#9: Are You Sure That Was an Accident?
If anyone has ever worked a cash register or a credit card machine, they would likely know how this sort of mistake could possibly happen. Nonetheless, the employee should really pay close attention to it, especially if they don’t know what they’re doing and have never used it before.

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When in doubt, really, just use cash. That would fix so many of these problems, even if it might raise a few other ones, like having to be more alert for thieves and pickpockets. Just hide some wads of cash in your socks; problem solved.