I'm not entirely sure if that was intentional, but it's really unfortunate. I've experienced similar situations at fast food drive-thrus before. After you hand over your money, they prepare your order and then close the window like nothing happened. It's funny, but I can't help but think, "Hey, where's my change?" And then I realize I didn’t receive it! Despite this little hiccup, I really appreciate the effort. I love Wendy's, and I suppose you never fully understand what an employee can manage until they're faced with responsibility and trust. I don't hold this against them; I'll definitely keep going to Wendy's. Better luck next time!
