Odds are that they don't care how much you abuse them or how many times they have to restart with another ad etc, they will always find enough suckers to pay their bills.
If you really want to fuck with them, make bookings and don't show up. This will either waste their time or encourage them to double book which will piss off more punters and eventually turn more people off seeing them.
If you want to see them stopped, don't give them any warning and just report them to PLA/police.