How can i get documentation from a past criminal charge, stating that the case was closed?

well i applied for a good job, and they did an extensive background check. they found a charge for larceny against me from back in 2007 when i was in basic training at fort jackson sc. well i was never charged or arrested for this offense i don't know how they even got wind of it. does anyone know a way i can get documentation stating that this charge was dropped or otherwise not in affect. FAST!