Default Unlocking Galaxy S 3 sch rm530 from MetroPCS

Hello, I am trying to find out if it is possible to unlock my phone, I have a Samsung galaxy s3 sch 530m from Mertro Pcs, It has a sim card slot but when i insert my sim card nothing happens also when i try dial in codes in the dialer like *#197328640# nothing happens. Could someone please help me with this thanks in advance.