I can well imagine this to be some kind of hell that is not easy to deal with. I do not know what kind of practical advice I could give in such a matter. But I would like to mention some points that you perhaps may consider.

- They are kids, and as such you should be aware that there are some special reasons why they are like that in class. I do not know if it would be of some help to talk to the parents and to find out more how they are outside class. Perhaps, there is too much pressure on them from outside class that they take the situation in class as an opportunity to get out of control.

- Would it perhaps be a good idea to approach some of them individually and find out why they are like that? Try to build a personal relationship.....If they really like you, they might also show more "discipline"......

- If you show them or make them feel that they are "hell" to you, they will not bother not care; they might even try to make your life "more difficult". Again, it may help if you could demonstrate on some occasion that you "like" them....

May be, there are some other barriers to overcome. Try to identify them, ask your colleagues for advice, and remain "cool". Yes, easier said than done but I cannot see any other way to get through the next few months in a reasonable manner in any other way than that.

If you really feel that you can't cope with this situation at all, ask to be given another class to teach.

Are you teaching in a Western or a non-Western (e.g., Chinese) environment? Approaches to solution may differ according to cultural patterns then. My advice might have been more concrete if you had mentioned some details in this respect.

Good luck!