My ipad2 3G suddenly not fuctioning

Plz help. my ipad2 3G is not working. I've contacted the carrier and has confirmed my SIM card is active and no issue on it. I've restart, reset APN, reset networking setting & until the extend, i factory reset it as new.. Still not working. My IOS is 6.1.3.. I'm helpess & dont know what to do now.. PLz help me.. TQ