If they have had such angry customers that they need bullet proof glass, they need some SERIOUS communication training! Possibly adding words like 'please,' 'just a moment,' and 'thank you' would save lives until that training can occur!

I seriously doubt that things are that bad, however. The training for them to feel safe and feel clever, engaging, happy, etc., is psychological training and what I recommend is what I call "Self-Image Thinking Training" - the theory and much of the protocol is explained in a chapter of my book THE ANSWER WITHIN.

I hope that helps.