Hi
If it were me I would now write a polite letter to the Divisional commander (or go and see the Duty Inspector) and explain the basic's of the offence including that the OIC 'assured' you that you would get the money etc. Explain you are disappointed that VS couldnt answer your query or wouldn't make enquiries on your behalf so you contacted the OIC directly only to be told that the case is closed. Explain that you require very simple information iei what enquiries did the investigator make to locate the stolen item and what actions were taken, did the police submit an application to the prosecutor, if yes what was the outcome etc etc and of course, ask if you are entitled to this info in accordance with force policy and The Victims Charter 2006.
I wish people could see what nonsense really goes on within the police service and how badly victims of real crimes are treated