I found this website about how to stop puppy mills and what exactly they are. It has kind of a checklist to answer if you think it's a puppy mill and if any of the answers are yes then that's what it is and more info on how to stop it. The website is
www.canismajor.com/dog/puppymil.html and
www.canismajor.com/dog/stopmil.html ! I hope that helps you out.