Its a matter of principle, don't you dare back down, because if they do it to you and get away with it, they will do it to the next unsuspecting decent person. These people are nothing more than scum bag bullies, who truly believe they can do as they want, and scare the living daylights out of you.
And if you think you can't take anymore, remember this, you are not the one who has done anything wrong, never doubt that.
Lynn