Has the Society ever cited this document in support of its rights? If so, I hope Article 18 didn't escape its notice:
Article 18 - Everyone has the right to freedom of thought, conscience and religion; this right includes freedom to change his religion or belief, and freedom, either alone or in community with others and in public or private, to manifest his religion or belief in teaching, practice, worship and observance.
From Wikipedia: Freedom of religion is a principle that supports the freedom of an individual or community, in public or private, to manifest religion or belief in teaching, practice, worship, and observance; the concept is generally recognized also to include the freedom to change religion or not to follow any religion.[1]The freedom to leave or discontinue membership in a religion or religious group —in religious terms called "apostasy" —is also a fundamental part of religious freedom, covered by Article 18 of the Universal Declaration of Human Rights.