They confronted them when they paid and told them never to come back.
That seems reasonable to me.
One last chance to not waste a bunch of food, and when they failed, that was that.
They paid upon leaving. It's in the story.
Some places make you pay upon entering. The way this is worded, it looks like they paid, then ate one plate, then were told to leave.
Dershem said she paid her $5.95 fee on Saturday but was abruptly told to leave after eating one plate of food.If it were me, I would not be a food waster, but I don't think I would have paid after just one plate.