My friend borrowed money from me

Iam student from mumbai I have given 17000 to my close friend.In two installment 8000 & 9000 respectively. As he was trustworthy friend I trust on his words that he will return my money after 1 month and didn't signed any document. Drastic part is that he invest that money in share market and also borrowed money from others people and loose it..he also use his father ATM to withdraw money without permission and invest that money in share market.. Now his father have stop him from attending college also he has instructed him not to contact anybody (I think so) . his number is off from past 24 days.he comes online but didnot reply to my mail or msg.. I talk with her father but he is not sounding good.. He said me in anger that you have given money to your friend and Iam completely unware of it also my child invest all money in shares and loose it . he also loose my money without my permissions.. And he is telling me you dont give money to me dont call me..and forget about your money.... What should I do plz help Money was transfer by me online with captions of my name..that is only evident of transferring money as I didn't signed any document with him.. Thank you