Cash Back Attack, Part 16

I am ringing a woman up for her purchases.

Me: “All right, your total is $21.57!”

Customer: “I’ll pay $20 cash and put the rest on my card.”

Me: “Great!”

I take the $20 bill she hands me, but since the drawer only opens after all the payment is done, I just keep it in my hand.

Me: “Okay, that leaves $1.57.”

She inserts her card and pushes a few buttons, and I get a prompt on my screen that she has asked for $40 cashback. I look down at the $20 in my hand. I look up at her. I grab another $20 bill out of the drawer, add it to the one she just gave me, and hold it out for her.

Me: “Here’s your receipt and… $40 cashback?”

Customer: “Thank you!”

Then, she took the twenties and her shopping and walked away. I wanted so badly to grab her shoulders and shake her and beg for an explanation.

Related:
Cash Back Attack, Part 15
Cash Back Attack, Part 14
Cash Back Attack, Part 13
Cash Back Attack, Part 12
Cash Back Attack, Part 11