You have identified the two different options you have:1) You can report the equipment as stolen, but be aware that while the police *should* intervene in a case like this, they often refuse to--even though illegally retaining your equipment is a crime, they will treat it as a civil dispute, since they want to focus on more socially serious and less ambiguous crimes, like drug use, assault, etc.2) You can sue for the return of your equipment. Note that you may need to sue in civil court (i.e. country or municipal court), not the small claims section or court, since what you are suing for is injunctive relief--a court order that they let you get your equipment. You can still represent yourself if you like, but the rules are a bit stricter and the filing fees slightly more expensive. Contract your court's clerk's office and ask the clerk which court to file in; he or she will be able to tell you, and also point you to instructions, sample forms, etc.