Just to follow up on what lowcostdolly said, I experienced an extremely unprofessional safety briefing on FR a few years ago. The cabin crew member announcing the brief was in fits of giggles and had to pause the announcement on several occasions in order to recompose himself. The demonstrating crew members weren't much better. The passengers watched in stunned disbelief.
On disembarkation, I asked to speak to the captain to report the unprofessional behaviour of his crew to him directly. I was refused permission to speak to him. Since the aircraft's commander wasn't interested, when I got home I decided to write directly to the airline's chief executive explaining exactly what had happened. I received a letter by return within two days stating that the cabin crew on that flight would be 'disciplined'. I don't know if that means dismissed, but if they were fired they deserved it, I regret to say.
So yes, the airlines do take breaches of safety regulations seriously, even if that means going further up the chain to get your complaint noticed.