Try working drive-through at a Taco Bell.
Night Shift.
Next to a strip of hipster dive bars.
"Welcome to Taco Bell I can take your order whenever you're ready"
I'll have a burrito.
"Uh...What kind of burrito?"
A BUH-REE-TOW. What? Are you fucking retarded or something?
There was one night when these two guys roll up and every time I handed their drinks, they would change their minds. "No, I said Dr. Pepper" "Nah son, I said SPRITE"...after about the fifth time the driver chucked a large soda in my face. I was soaked head to toe. I lost my shit and chucked one of the other sodas at him, into his car. Got him, the passenger, his laptop, camera....everything. The guy and his friend jumped through the drive through window threatening to shoot me with a gun he didn't have. luls. The mexican girls I worked with started screaming in spanish, the passenger started smashing the register and monitor, and my coke-fiend manager locked himself in the office. All I could do was take apart a pair of kitchen scissors to use as a weapon if need be.
Cops got them an hour later, but I had to finish that shift covered in soda, and had to do it with a calculator and notepad.
FUCK customer service.