I worked at a book store, and the card readers processed everything as credit. Which is generally fine, since most folks' debit cards can be run either way.
I had an old dude come up and pay with his debit card. When it didn't ask for a pin, he started screaming at me about how I'd just illegally charged his credit card. I politely explained that it didn't work that way and he just kept yelling. So I rudely explained that it didn't work that way.
Dude, you think you inserted your debit card and that magically, our system somehow found out your credit card information and charged that instead?
Ooh, that's some memories. My grandparents lived in this area and even when I was a kid in the 90s this mall was in rough shape. Being from somewhere with no mall, I thought it was awesome anyway.