Boiling Over An Ice Cap

I work drive-thru for a popular coffee chain in Canada over the summer nights. There are only three of us. A lady orders a coffee, black, with five caramel shots. I make it and hand it to her.

Customer: “No, I wanted an iced coffee with caramel.”

I make it the same way as I have many times before. I get to the window, charge her the difference, and then hand it to her.

Customer: “Are you f****** kidding me? I wanted an iced coffee with caramel shots!”

Me: “This is an iced coffee.”

Customer: “No, it isn’t. I wanted an iced coffee.”

I stop and think. I’ve worked there a little over a month and made it many times; I think I know what it is. I think logically, and then ask:

Me: “Did you mean an icecap?”

Customer: “No! Iced coffee.”

Me: “Did you mean a regular coffee with ice in it?”

Customer: “F***, just give me an ice cap.”

Me: “I can’t, not without the upcharge.”

She then tried to chuck her Thermos at me. I slammed the window shut and ignored her. My coworkers said not to worry about it and that all the confusion was on her side. Later that week, she was named for pulling the same stunt and actually hitting a worker, covering them in hot coffee.