Wait.... Hold on now....calm down...
If you have an injured animal, you take it to a private vet.
The Humane Society is not that; animals are only inventory to them, and any problem or issue animals are quickly discarded; they put-down so many perfectly healthy animals anyways, so they cannot be convinced that their protocols are wrong.
That the man couldn't afford a vet - not their problem
That they don't take credit-card payments over the phone - they're not in a retail/service business
That they acted coldly and calloused - did you ever date a nurse?