Does the letter provide evidence that the contents of the library were unavailable to them if they didn't have NGO status?
Is there any evidence anywhere that the contents of the library were unavailable to them if they didn't have NGO status?
I'm not aware of any rules that would have denied them access to the library or the contents, only that they had to apply ahead for a day pass if they wanted to visit Dag Hammarskjöld. If that is correct, then there was no NEED to join and their excuse is BS. It is up to the person making the claim, that they needed membership for access, so it is up to them to prove it.