Job consultancy kept my original marksheet

A job consultancy kept my original marksheet for giving me job. They told me they provide me 5 to 7 interviews within 15 to 20 days. In this day they provide me 5 interviews but none of them is suitable for me. I'm not interested that type of job so i refused that jobs. When the HR keep my document he told me if i discontinue in 20 days so there will be a penalty charge. After 20 day, 5 interviews when i asked him to give my doc back they refused me and also said that i have to paid penalty charge . So that i go to the local police station complaining they not take my FIR, police told me that next day if i go the consultancy office and call him by phone then he will talk to the HR and manage my problem. That evening Some moments later after leaving the police station i received a phone call from the consultancy HR.. He politely threaten me that "you go police station. Well go for another police station next day.you can not do anything to go police station. Where you stop i will start from there. You are vary small to stop me". Now this situation what can i do for my document bring back? The HR give me a written latter with company stamp for taking my document where he wrote that he keep my document for 5-7 interview in 15-20 days. And i also have video footage of his oral conversation. Plz tell me how can i bringing my document back. I am very frustrated for this situation. Can i able to withdraw duplicate marksheet from west bengal board of higher secondary education, and is it will be valid for my future? Or i have to bring my doc back from the job consultancy?