The Shipment (2000)

Convinced that their new partner, Stacy, is actually an undercover cop, Brenda and Murray decide to grab her, tie her up and, when they've made their big drug deal, send their former friend to Davy Jones' Locker. But their new "supplier" is actually the leader of a rival drug gang and soon Brenda and Stacy are both stripped, bound, and gagged victims with an uncertain future.