More than likely the breeder fed it live hopper or rat pinkie before the purchase and after you returned it to him. Also, it was probably living in a small bin in a rack system like all the other hatchlings. This is not counting the temps and humidity the breeder have right in his room.
So imagine that and your snake being shipped back and forth, living in an unfamiliar place and eating a strange prey item that he may not recognize. It is a huge stressful move for your snake.
There is a 101 hatching feeding sticky by Deb in the forums. Follow it and you should see it eating soon.