Sometimes the only way to stop bullies is to tell them exactly what will happen if their verbal abuse continues.
A basic polite threat word block works like this: 1. ACKNOWLEDGE their feeling "I can see that you don't like me......." 2. EXPLAIN THE CONSEQUENCES "but you would not want the teacher to hear you saying that, would you?"
As with humor and apology word blocks, you must respond quickly and without a trace of anger or emotion. Keep working on your Mushin!