If your contract didn't state that the dog was specifically AKC registerable, then I'm not sure there is much you can do.
In your conversations leading up to the sale of the dog, did the breeder ever actually say he was AKC eligible? If the breeder has a website, was there any misleading info on it? I really don't know much about the world of kennel clubs, and hopefully someone else here can give you some good advice.
I'm sorry this happened to you - some breeders' lack of ethics are absolutely astounding.