I'm sure we all hope that Yogi has a happy, healthy life. And I'm sure the OP would have done things differently, had she been informed.
We all know the pet shops prey on the emotions of people. (not trying to be sexist here) But women are more emotional, and are easier prey for pet shop owners. I bet I can almost nail the pet store sales pitch.
About the only defence available to us at this time is to get the public informed. There are peeps out there trying to do just that. Please join them in trying to spread the word.
http://http://www.facebook.com/#!/thepuppymillproject