Was it rooted before the SDS?
As far as i'm aware samsung handsets come with a 2 year manufacturers warranty so If you bought if in feb 13 it should still be covered.
If it was rooted then charging to fix it is fine since that voids the warranty. But if it was a samsung repairs center and THEY tripped the knox counter...
Maybe i'v miss read something but if it was tottaly stock then i'd have pushed for a free repair/replace.