If not bring him back, can you arrange play dates with his littermates? They learn all sorts of things from playing with littermates at that age--bite inhibition, the first lessons of good dog manners... If you can get them together you'll be so much happier in the long run--the lessons he learns with them,
you won't have to teach him later.
He sure is a cutie!! But we'll need more pics to tell for sure.

(Yah, I know...pretty transparent excuse for getting more pics

) Have you got a name for him, yet, or will you base it on his personality?
He and Bully look like they're fast friends already.