I teach a sixth form class who have not been like any other I have ever taught. They will listen to me when I am teaching but as soon as they should be working they just....well where do i start: -wind each other up -try to be funny when in fact they are annoying -focus less on the task and chat ALL the time -they genuinly think they will get the top grade despite me telling them that they wont due to the poor attitude -throw paper and foul language which I have reprimanded them over etc etc] I normally treat sixth form as adults because they act like it, but this unpleasant bunch are very childish and immature. I am at my wits end with them and think this may be my fault/doing. I also feel it is completely unfair to the one very nice quiet and hardworking child to be in an environment like this. I have reported this back to my seniors but nothing has happened. I actually go home feeling stressed and unable to get a goodnights sleep because I am thinking of the disastrous lessons I am having with them. The next morning I cannot focus enough due to the lack of sleep. This is a job I love and I enjoy teaching all my other classes very much. What do I do?