i have a iphone 1.1.3 unlocked..i gt it 4m us..i stay in india..the phone was working f9 there but whn i came back to india it started gvng me tis problm..the thng is i can receive calls and messages...i can evn send messages but i cannot make any calls....whn i dial a number it shows call ended and i gt a option of call back or cancel...i cant understand what to do...