Unfortunatly, with rescue groups, I've only heard of using one vet office- though come to think of it maybe not, definetly worth asking! some vet offices have more than one vet- wonder if you could just avoid appts. with that particular AH!! Don't be insulted too bad, they were very rude but it's not you, it's THEM! Well, you know that but just saying I agree with everyone here, what you are doing is so special and the vets just don't appreciate that! I too have had my share of unruley vets.... I had to learn to ignore them out of sheer no other choice! (then gossip about the vet with other rescue people!- helps lift the strain a lot!)
Hang in there!