I've had the same experience of the RSPCA…
Stray dogs, they don't want to know. Injured dog/cat etc lying by the side of the road, they don't want to know. Neighbours mistreating their dog, they don't want to know.
I think they quite like swans and stuff, especially if there's a TV camera pointing at them. Sometimes I think that if people knew all the stuff they didn't do (which people seem to preceive they do) then they wouldn't be one of the richest charities in the country.
I've never been able to get them to do anything.