Iphone 4 black 16gb no service ?

iphone 4 16gb no service blocked to 02 absolute mint condition 9/10 more or less new no scratches on the back glass and two little light hairline scratches to the front barely visible only seen when phone is off,phone was working when brought stopped working after a couple of months and only used for music, everything else works apart from making calls, could be used for music videos, gaming and browsing via wifi comes with box but no accessories brought iphone 4s so no longer needed everything is back to factory settings it has the latest firmware 5.1.1 only genuine buyers and no overseas buyers thanks any question call 07791315284.