Hi!
I'm facing the same problem as you but with younger kids, as I teach 1st,2nd and 3rd grades.
With younger kids there are things that we could do, such as: talk to them alone, tell them that you will talk to their parents(this is something they fear) and I also use a behaviour chart.
In each lesson every student gets a face on the chart( a sad face if they don't behave or a smiling face if they behave and work).By the end of the month the students with more smiling faces get a prize( candies or something small but they enjoy it).
So far my students are getting better behaviours.
Good luck!