I wouldn't beg the Humane Society, because they probably won't suddenly change their minds and go against policy (I used to work at a couple different Humane Societies and I know there would be HEAPS of trouble if any employee ever gave out information like that).

I would try Karen's idea though. If that doesn't work, then there is not much else beyond that you can do. Unless you want to run the story on the news or something.