To begin with, write a written request to the management to reimburse the cost of the jacket that the wardrobe lost. The administration of the institution must respond to this application no later than within 15 days.
If you received a refusal or no response - contact the court. Attach all possible evidence to the statement of claim:
ticket to visit the institution,
paper on appeal to law enforcement agencies,
management's explanation or response to your request.
When filing a lawsuit, do not forget about a document confirming the value of the stolen item (for example, a receipt or a receipt for the purchase of goods). If you cannot find the receipt, contact the administration of the store where you purchased the lost item.