Dear Silvia,
Your problem is one which many teachers have.
Some students think that school, college, or university is a place where they will be able to gain the admiration of their fellow-students.
Sometimes it is because of ability in sport; sometimes it is in attracting the opposite sex; sometimes it is in passing an examination. These are all understandable hopes and wishes.
Others gain the admiration of their fellow-students by becoming leader of a recognised group; for example, the Leader of a House, or a Society, or a Club.
However, some students --- particularly some under-performing students, particularly some boys, particularly some older boys --- attempt to gain attention by becoming leader of a gang, possibly involved in drink, drugs, etc.
One of these gangs is �The Gang of Bullies�.
Their purpose in life is to make life a virtual Hell for their �victim�.
The �victim� is often the �Teacher�.
There is only one way to defeat Bullies. Make a record of this disgraceful behaviour, so everyone in authority, and the Parents, know about it.
If I was in your position, I would, beginning tomorrow, always bring into the class a sheet of paper with a squared Grid.
Down the side would be the names of the known �Trouble-Makers� in the class. (You can easily add a name or two).
Across the top would be the Misbehaviours --- �Talking in Class�; �Walking Around in Class�; �Interrupting Teacher�; �Insulting Teacher�; �Not Working in Class�; �No Homework Done�; �Class Exercise Not Done�; �Shouting�; etc. You know what the problems are.
I would write these �Rules� clearly on the board; ask the worst Trouble-Maker to read them for all the class to hear; ask each student if he/she understands the Rules; and then Photograph the board as evidence, (in case a student �didn�t understand� what was being said).
From that moment on, every time there was a Violation of the Rules by, (for example), Student X, �Talking in Class�, (for example), put a tick, �, in the �Talking in Class� column, against Student X�s name.
DO NOT TELL THE STUDENTS WHAT YOU ARE DOING --- DON�T ANSWER QUESTIONS.
If you do, they will go to the Head Teacher with more lies!
At the end of the Lesson/Break/Day, I would show the list to the Head Teacher and explain what I had done, naming the culprits and their misbehaviour, and saying that, for your own protection against the lies of the students, you intended to do this every day. You also want the Head Teacher to include this information in a Letter, Reporting to the Parents the bad behaviour of their children.
At the next Lesson, I would tell the students why I was writing in the Grid, that I intended to keep a daily written record, and that, with the agreement of the Head, I would inform the parents. If there was subsequent improvement in the behaviour, I would, of course, keep a record of that, too.
I do not know the legal situation in your school, so a Word of Warning.
Obey the Rules of your school.
Treat all of your students with politeness and dignity. They are not ALL Trouble-Makers.
DO NOT write, say, or do anything, which infringes the Human Rights of the students. DO NOT disclose any material which reveals personal details about your students to any person or group not entitled to that information.
I hope that I have helped you slightly.
Les