If you already know what's coming, I suggest you bring a sharp object with you to dismember the boss after you've finished murdering him for firing you.Just a thought.
This is of course assuming that the person actually told you that. Don't forget you're dealing with the Choir. I don't supose you can read lips? That might help you tell what your boss is really saying if They put words in their mouth.
I would suggest getting people to write things down for you, and ignoring everything you hear. Working in a call center I admit will make this difficult.