this happened to friends of mine at a Chinese restaurant in NYC. They made a reservation for 30 people and only 22 showed up on the night. The restaurant however, told them at the end of their meal that they would have to pay for 30 places and that this was their policy. They were not told this on booking the table but only after the meal.
Is this valid and has this happened to anyone else? They all coughed up the extra money but were obviously not happy with the arrangement and would not return.