I think you got two stories mixed together.
Traded by JennMarie is about a boy given to a Russian Mobster, but he never goes to the police.
Muffin and Matthew are by Mahsa, they're also about a boy who has a relationship with a mobster, but he goes to the police and then runs off.
http://members.adult-fanfiction.org/profile.php?no=1296864194