Someone below said they were rude. I think that's even more than that. They will do everything they can to make your life difficult, they will treat you like a nobody and throw accusations in your face. They might look like a respectable agency if you don't know them, or only have to deal with them occasionally. Yet never ask them to be helpful, and never tell them you disagree with them or that's the last sentence you'll make: they will say the rest for you.
Run away, this is the best advice I can give...