First, are you SURE they were pellets and not starter? Regular chick starter can appear pretty large next to new peeps.
Second, I would speak to the manager before reporting them to animal control. I would not want to do anything to discourage a retailer from offering live chicks for sale when such problems could hopefully be corrected by a little education. Odds are good that the person in charge of the chicken display is not nearly as knowledgeable as most of us are.
I am on a gun board and I hear the same lamentations about the stupidity of most gun shop employees because God forbid, they are just working there for a living and are not gun experts.
Please let us know how things turn out.