"teachers are not allowed to discipline them in any way or form."

Not true. 
I worked with 'difficult' kids for almost 40 years, first at a reformatory and then as a teacher of children with social-emotional & behavioural problems. Like many teachers I worried when the strap was banned in the 1980s but it soon became obvious that it was the correct decision. 

There are many effective strategies that can lead to significant improvements in attitude and behaviour. Unfortunately, teachers' colleges usually don't provide much training in behaviour management and some principals may not support the imposition of certain kinds of consequences. 

The result is that chronic misbehaviour is perpetuated when it could have been stopped by consistent in-school consequences. When in-school responses are ineffective the usual result is chronic disruption followed by a suspension. If that fails to bring about a change in attitude and/or behaviour then the cycle is repeated... with little benefit.