they have their right to do what ever they want. it's also ur right not to go with them again (that's what I would do).
I'd never to such a thing to a pug member who came to fill up the spot, we try to be nice and helpfull to people, and it pays off. often on GF daily, I hear 'oh, cool, I love playing with ur guild' and it's nice thing to hear.
Some preffer other reputation like 'oh noes, it's those muppets again, this is going to be a pain', it's their own choice.