If you care about the content of the conference, and/or you like to talk with some of the recurring participants, you could go to the conference next time and confront the organizers directly, since they won't let you do it online.

But in terms of feeling rejected for unknown reasons, I'd let it slide. The reactions you describe (twitter blocking, "we don't have time to answer" emails) are immature, so expecting more from them is naive.

Since they haven't said "please don't attend again", don't interpret it that way. Don't reward people for communicating this poorly. If you can buy a ticket in your name, and you want to go, go. :-)