You may not want to bother with it, but I would send an email or a letter to the club president and cc the chief instructor about your experience. My club is very outgoing and very willing to help a newbie, but there are a couple of older instructors who will do exactly as you described- ignore an adult pilot who should be next in line in order to work with a kid. They way they see it, it's their trainer plane and their time so they can use it to work with the student they want to. I think that's the wrong attitude to take, but they aren't going to change. So if a new pilot were to work with one of those guys first, he would get the wrong idea about our club. I'm a believer in giving a club a chance to show you what's good about them.