Strictly speaking this is an English Language discussion forum so this post doesn't really fit in here. However, have you discussed this with your head teacher? What advice has s/he given?
If it were me (and I'm not a teacher), I would remove the disruptive pupils from the classroom. School policy may not allow this of course, but if it does then remove them. In my opinion you have no duty to teach these pupils if they won't abide by normal social rules. In the end the loss will be theirs.