If there were an audience to this dispute there might be some point in continuing, but since it's in private, I think you should bow out by briefly reasserting that his organization has taken liberties with the sacred image of a patroness whose feet we would be called blessed to kiss, and they should be ashamed. Whatever charitable works they have done they could have achieved better under a respectful banner. You could add (and I'm assuming now) that you are no longer interested in participating and will be warning away friends and family. But your emails are unlikely to affect this fellow.