“A Time You Dealt With a Difficult Customer”

Vent it out however it comes — the editing is the job here. Most of what you write about how the customer behaved gets cut, and what you actually did gets expanded, because that's the only part being scored. If you can, include two things: the moment you chose one path over another, and anything you changed afterward so it stopped happening. That prevention beat is what separates a good employee from someone worth promoting, and almost nobody includes it. Leave it blank and you'll get the structure with placeholders to fill.