Sign in Failed

[AC Question]

So I Bought A Tab 4.0 From One Of My Friends I Decided To Reset I And Went All The Way Till It Said Samsung Sign In. So I Called Him And He Came Over And We Keep Trying To Sign In. So After About 30 Minutes It Says Sign In Report Sent To Samsung Account Email And We Haven't Got It. And If I Take It To Best Buy Can They Fix It