All Of The Calories, None Of The Taste

(I work as a cashier at a local fast food place. A young woman approaches me.)

Me: “Hello and welcome to [restaurant]. Can I take your order?”

Customer: “I’d like a medium Diet Coke.”

(I get the Diet Coke and give it to her. She pays and leaves. Five minutes later, she returns looking rather angry.)

Me: “Hello, did you enjoy your Diet Coke?”

Customer: “NO! This isn’t Diet Coke! I can taste the Coke in it!”

Me: “Uh… let me get you a new one, then…”