Untrained pet store workers!

My hamster just lost all of her babies. They died of unnatural causes.(Aka: Mama ate them from stress) She was too young to have them and I blame a pet store in Illinois for it!We were visiting and they had the perfect hammy! Beautifully colored, active, everything I was looking for! The horrible pet store paid no attention to the genders of the hamsters and just threw them into one cage. We asked if she was a boy or a girl and the said it was to young to know, my aunt looked and said" oh, its a boy!". It wasn't. we got her home and she had the babies. THey lived to be 4 weeks. I was looking forward to seeing them walk, but it never happened.