Hatchlings or young BP....what to expect

Very new hatchlings actually look fat. They are still absorbing the yolk. Then they go into a shed, and after that shed is when many breeders then attempt a feed. The snake that you described in the OP sounds like maybe it has either never eaten, or got stressed in shipment to the store and is not eating now. Personally, I do not think that they should have a nonfeeder on the sale floor; the snake needs to be secluded, allowed to become comfortable without gawkers, and get steadily eating.
Unless it is feeding, and they are just being stingy with the frequency of feedings..

Thanks for the extra input! I feel a little more prepared to approach the manager of the store IF the poor little guy is still there.

I'll make a trip out there early this week and update when I do. Wish me luck! Rather, wish the little guy some luck!

Ask what that snake is eating and how often. I'm always amazed when I find out quite a lot of big chain pet stores offer only tiny pinky mice to young ball pythons. :(