Cheating/froud

Respected Lawyers, My commercial property was sealed by Nagar Nigam, so I met a person who claimed that he has good links in the department. On 06/01/2014 he told me the expected cost for opening the sealed commercial property will be around 2.5 to 3 lakhs and he need rs 50,000 in advance . I agreed as he told me that the work will me don within 30/45 days. Till 23/02/2015 he took around Rs 4,50,000 from me and now as on 22/01/2016 situation is still the same , my property is sealed and he is not returning the money . when ever I ask him about my money he starts fighting . on 16/01/2016 he even threatened me of dire consequences. I was and I am still in touch with him and after I realized that he is cheating , I started recording calls and even made few videos in which he confess of taking the money. I am quit tensed from 16th of this month as he is not returning my money and threatening me.I did some research on net and came to know about few laws and above all this beautiful website where I can discus my problem.Please let me know how should I handle this situation as. 1:- I have many audio and few video in which he confirms that he took money from me but is audio a valid proof moreover I don't have photo or video of giving cash to him. 2:- I came to know few laws like 415/420/120b for fraud and 506 or 508 for threatening. Are these Ipcs applicable in my case. 3:- should I send a legal notice to him as I have audio clip in which he told me he will give me the money on 20/01/2016 which as usual he didnt. Please help he ,