You came into the restaurant today, mother and daughter, and you sat in my booth. You ordered steaks, one medium-well and the other well done. You both wanted broccoli and mashed potatoes, and I was happy to oblige.
I got a little busy, so my manager ran the steaks to your table. I ran by a minute later as you were eating and made sure that everything was okay. You said it was. Great, everyone’s happy.
I run the bill, you say everything was fine.
I come back to collect the bill and you stop me before I open it, though I see the corner of a dollar bill, so I know you’re paying in cash. “Do you want any change?” I asked, and you smiled and shook your head.
“No thank you,” you said. “But you should know, you switched our steaks.” You pointed at the single, bite-sized piece of steak left and scowled. It had the slightest hint of pink. “That is raw. I know there’s nothing to be done about it now, just thought you should know.”
“Oh, I’m sorry.” What else could I say? You had cut into your steaks when I checked on you earlier. You were eating them. You were too stupid to switch your plates. “Can I do anything for you?”
“No thank you. Have a nice day!”
“You, too.”
So I walked away and went back to process your payment as you walked out the door.
You left me fifteen cents on $25 because you were too stupid to switch your plates.
You left me fifteen cents. I paid to wait on your stupid asses.
I thought that I had hit the low for customers, but this industry never ceases to shock and amaze.
-Hanna
Break Room Stories 
And since we servers pay taxes on our sales, you ended up paying for their steaks. They had no intention of tipping. The good news is that karma will get them.
I’m so sorry you had to go through that. No one deserves to experience such cruelty from an imbecile such as she.
Bottom line here is that they are simply, inexcusably, cheap. Most likely, they never tip anybody for anything. They concocted this flimsy “excuse” to rationalize their ugly behavior. They know exactly what they did, why, and how ugly they truly are.
Stupid people!!!!
Uggh I’m sorry. People suck!! Like you said, customer-service stories never cease to amaze me.
That is just so petty and pathetic of them. I bet they think they’re so funny and clever for doing that. When they share this experience with their friends, I bet the friends are also going to say ‘all you had to do was switch your plates!’
Some people!
Many MANY people (most) give humans a bad name! Cruel, mean, exploitative, greedy and just plain ignorant. Sorry you had to experience that.