As I read Jeff Ooi's ScreenShot blog today, this particular post really caught my attention as the exact same thing happened to me last year! Many users came up with copy of their phone bill, showing irregular (mostly exorbitant charges) transactions on SMS's received
Look to my previous post here, and you could learn a thing or two on how to safeguard your precious number. If you're lazy, remember this:
CHECK YOUR PHONE BILL EVERY MONTH!