Good for you for educating someone else about the horrors of buying a petshop puppy (usually)
I would also suggest that you not shop there again as well. I buy from Petsmart and online excusively. But that's me. I know how you feel. There was a pet shop at Pismo Beach here in California and I couldn't help myself and ask to hold one of the puppies. They told me that unless I intended to buy it, that I couldn't hold it. Funny, huh? So being the meany that I am, I asked where the dog came from, if they support puppy mills, all kinds of things. I know I made the employee uncomfortable but I couldn't help myself. I too spoke to a few other customers and recommended they search for "puppy mill" on the internet before buying from a pet store. I'm not sure if I made a difference, but I tried