How can I get money back from someone legally?

I have given money to friend 50000 for 2 month. It is more than 3 month. I have done payment through google pay. I don't know where my friend lives. He is responding my phone call. On WhatsApp he is saying I will return as soon as possible but he is not returning at all. Even went to police station lodge complaint but they refused my complaint and said it's your fault.