got scammed for 8$ by this user : johnjack

https://bitcointalk.org/index.php?action=profile;u=629555

he ask 10$ for a local card that have 5$ , i said 8$
he said ok , then i sent him 5$ to try it then complete whit 3$ if it works and he said ok
after i sent him 5$ he send me card number when i tried it it dosn't work
he said he need to activate it and i have to send him the 3$ to do this
i said ok but if it dosn't work you refund me and he said ok
after sent him 3$ he claim that hi ask for 10$ else he will not activate it and refuse to erfund me