I have no words

At work today, I witnessed a group of students who had no concern about being rude. It was astounding. The teacher would shout out for everyone to get into positions for the scene, but no one did it. I'm pretty sure they heard him, but they just didn't respond. In fact, during one such command they all gathered for a picture in the corner of the room. The teacher watched as they all smiled and giggled while the flash went off. Then they broke up into smaller groups, spread across the stage and continued talking. What do you do with a group like that? I'm not sure if in the British system you can threaten to fail them if they continued talking. Some of them are there because the government is paying them to attend in order keep them off the streets, so what would they care if they fail a course, they'll just pick one up next month and collect. Such profound and casual disrespect...I was thinking while watching the "rehearsal" what I would do to try and reign them in. But I couldn't think of anything, because I knew they wouldn't care no matter what I did. I have no words.