My first client does not want to pay

Hello I need help.

The buyer Adam S. Does not want to pay

I have done what he asked for and he just see the messages and he does not want to respond. He told me that if I finish his task he would pay me. After that I was doing his task during 6 hours.. After I finish the task I send a message and he asked me for my profile pictures from his tasks, I send him the pictures and when i asked for the payment he just read the message and does not respond.

Please help me this is my first client.