You don't mention the age of your students and I'm guessing they're teenagers (maybe wrongly so).
I understand your problem and the director doesn't seem very supportive. Is there anybody else in the school you can share ideas with or use as an authority figure to send students to?
It sounds as if there is a lack of respect which needs to be addressed as an atmosphere of making fun doesn't help learning. I suggest you make this your priority to tackle. Let the students know you won't tolerate fun-taking, talk about it as a whole class and ask the students what they think; they usually agree it's important.
I suggest you use some or all of these techniques:
Write up a list of classroom rules, possibly incorporating students' suggestions.
Use a seating plan to see if the situation changes when students are grouped differently.
Have a rising scale of punishment (from mild to more severe punishment) mapped out before going into class. Have it clearly in your mind and possibly written down. This avoids the possibility of using the most severe punishment first which leaves you with no other recourse.
Let students know how you will react to misbehaviour. If you make any "threats", you must carry them out otherwise they become meaningless.
What time do you arrive in class? With teens, it's a good idea to be there 5 or 10 minutes early. You then have an opportunity to talk with students, tell them where to sit etc. You also prevent disruption starting before the class which is then difficult to deal with.
You could use shock tactics. One or two lessons of writing or listening activities with no student interaction will put you back in control.
Arrange mini-tutorials where you spend time with each student individually, discussing progress etc. Be sure to praise all of them for some achievement and tell each of them how you want their behaviour or work to improve. Be specific eg "I want you to stop talking and listen when I am addressing the class". Not "I want your behaviour to improve". Follow-up is important here, praise improvements and remind them if they slip back into their old habits.
At all times be firm and fair. Be careful to model behaviour that you want to see from them.