Legal Question in Business Law in Washington

You'll want to look over the terms of your agreement with them. You'll want to, if necessary for the future, modify your agreement to include certain provisions such as the right of reentry during business hours to retrieve, and the right to attorney fees for actions on recovery.

You can attempt to contact the police, but, honestly, they almost certainly will not help ("It's a civil matter" is a phrase they like to say despite having zero training in what a civil matter is and a minimum training in what constitutes most crimes"). From there you go to small claims court, or district court to sue for possession, costs, attorney fees, etc.