Hi! I think you were amazingly self-controlled, and put your points across.
It's good to let your parents know your boundaries. Speaking from my own experience, can I warn you that you may probably have to do it over and over again? They just do not hear what you say. Kind of like the dog in the Far Side cartoon, you know, "blah, blah, blah, FIDO, blah, blah, blah, FIDO, they are programmed to hear what they need to hear. Try not to lose patience with them.
As Special said, it is unnatural for your mom to shun you. She probably suffers greatly because of this (as does your dad). Yes, it is not your fault! It is hers, but even moreso, the Society's fault. THIS is the fact that has kept me going in the relationship with my parents.
What has helped me? (not that you've asked) Realizing that I am in a much better place than they. I have my freedom, they do not. I am no longer controlled by the JWs, they are. If I think of it in those terms, it is much easier for me to deal with. I can feel pity for them, and direct my anger (usually) towards the WTBTS.
In that light, consider what it took for mom to call you. (again, I'm echoing Special K) Remember that, unlike many others, your mom and dad do love you, in spite of their crazy beliefs. Be the better person, forgive them and deal with them on that basis.
I, too, come from a family such as yours. For me, it helped to realize that my leaving the JWs was a huge blow to them. In spite of how much it hurts me, it usually helps if I remember that they are in a much worse life situation than I. After all, they are members of a cult and have no life whatsoever. I, OTOH, have lots of real friends and yes, an extremely dysfunctional family, but I'm gonna be okay. They are not.
To sum up, Good for you Elsewhere! Keep on keepin' on!
talesin