What can be done about "bashing" and moderators not allowing me to post?

I joined a group on which 12 members "bashed" an important project I was working on. One copied and posted names, cities, and states of petition signers, and went so far as to dig up those people's websites, etc., and post them in a manner that was chastising, intimidating, and "blackballing" the people who signed our "Molly's Law" petition. I tried to post a reply to answer legitimate questions and ask that the offending post be removed. My message was not approved, and the moderators' actions are in violation of their own "List Members' Bill of Rights". They will not allow my post and they will not reply to me regarding my re-submitting for approval. There was absolutely NOTHING wrong with my post, and I feel my rights to free speech, etc., are being denied. The "bashing" was damaging to my project, and they are giving false information to which I am unable to respond and set the record straight. What are my rights, and how can Customer Service help me? Thank you!