I found that when I got into pointless, frustrating battles with my ex-AH, it was better for me not to pick up the phone than to answer it and wind up in the mud with him.
I like a mud-free existence. I used to call his tendency for public battles the trailer-park fight. He would pick fights in public places, like big parking lots full of shoppers, and scream his head off at me.
Even then, I had choices. I could take a cab home. I could walk away. I could go shopping or get on the phone with a recovery buddy. Or I could stand there and make myself a point of curiosity or a reason for other people to want to call mall security.
I always had choices, and when I was sick and tired of being completely embarrassed and exhausted by my own reactions to his behavior, I made different choices.