Oh geez, this makes me SICK! If you scroll down on the main page and click on the breeds they have listed it takes you to the individual puppy pictures. SO MANY OF THEM.
That is not cool. If anything I think petstores need to stop selling animals and support local rescues/shelters.
I'd start by contacting your local SPCA. If this is a well known store, they may already be dealing with the store. If not, they also may be able to direct you to someone who can help further.