Coin Desk Traders欺诈

Forex trading investment,i still have the guy on my watsapped I met him on Facebook, he told me he will assist me in doubling my investmen within 3 days,I invested r700.00 with him promising to make it r7000.00 investing it on Bitcoin mining,only to tell me that my investment has gone beyond r7000.00 is now at r13000,00 and know must invest r1000.00 to be able to access my profit how possible can that be?