write up signs and rules for useing the equiptment , have the whole group sitting down before they go use it and let them know the rules let them know if they dont look after it then they wont be able to use it full stop

eg ,, what equiptment you take out to use its their responcabilty to pack it away

no bad words to be used

they have to repesct you and other staff as well as others playing

go over the rules every time the group comes in just to refresh their memorys

work out with the staff   what punishments is to be taken in to place ie ,, banned for a week from comming there etc,,

Turn off the sound, then turn off the lights, one at a time. Start packing up slowly. They will start to shut up and stare in stunned amazement at what you are doing. Eventually one will ask. You just cooly and calmly explain that you are receiving no respect from them and until you do you will not be coming to work. Check the reactions on their faces. they'll pull their heads in... for a while.

When they try to test your limits and see if you will in fact carry out your threat, do it again, but this time, don't stop packing up. Shut early. Re-open again as normal next time you normally would. If they start playing up again, turn off the sound... turn off the lights, one at a time...

They'll get the idea pretty quick.