Well, CVA, I just got yelled at by W, for her mistake, see my latest post if you want to know more so I don't really think I am in a good place to help you. but what the hey, I'll give you my thoughts, they don't cost anything.
So obliviously, she is confused by your actions, isn't that something, they want us to change and when we do and they see it, they question it.
I can tell by the way you handled the call, that you were most definitely in control from beginning to end, sounds like she isn't used to that, Good for you! Her deferring is her way of getting away from that, I know, mine does it all the time, I mean really if you were argumentative, and used your anger, than she would stand and fight, right? until she got mad enough and either you or her hung up the phone. Been there, too, still there. Not my anger, hers, happened tonight.
As far as the dreaded I don't know, I hate that one, myself, but that is the cry of the WAW, now isn't it. They think they know it all, but they really just don't know anything, do they?
I would say that everything you said, did need to to addressed, and you said it right, so you should feel proud. Keep up the good work, I don't know if that is what you were looking for, but I gave it a shot, Take care.