I have found dealing with students with behavior problems that disrupt the class to be one of the most frustrating experiences to cope with. My strategy is to take the student aside and listen to their complaint and try not to become defensive or judgemental. After the student has vented, work toward a positive resolution. If you are unable to resolve the situation with the student, it is wise to document the situation and follow your companies policy regarding the situation. And, don't be afraid to include a third party (instructor, supervisor, etc.) as a witness especially if the situation escalates or gets out of control.