I know you're very hurt by this horrible behavior, but please remember, it's the WTS who puts the screws to our loved ones. They muscle them into that behavior. It's not by choice.
If you want to be effective, in anyway, you have to be the smarter one. You HAVE to use psychology. If you go for the "in your face approach" you will only get hurt because they are brainwashed/brain-dead.
I would wait to cool off a bit before you do anything. When you're ready make a phone call. It's more personal and personable. You have to become the parent.....tell them you're calling to check in and see how they're doing. Call and send emails. If they give you slack, tell them that you worry about them and you have the right as a son to know how they're doing and it would be the loving thing for them to do.
Once they get the hang of you calling every so often....they'll slowly start letting their guard down. Hopefully they will later reciprocate calls checking in.
If you use any other excuse the repsonse you'll most likely get will be...."well, you know what the WTS says about associating or being friendly....blahha..blahha...blahhaaaaaa...
By them not staying in personal contact, they become desensitized, by WTS design. By you checking in they hear your warm voice, they see you haven't changed into a booggy man, their paternal feelings kick in. I took my own advice and slowly but surly seeing a difference.
Also *lost* has made a good point. There will soon be a WTS shitstorm in one way or the other! I can already see the change in my JW family members.