I have a prepaid series mobile no. which I converted to postpaid. But when I tell people that this no. is postpaid, they don't believe me because that particular no. series is normally prepaid. I want to change my no. to a postpaid series mobile no. while retaining all current services like name tunes, postpaid credit limit etc Is it possible? And is it worth to go through the hassle just for changing to a premium no. series?