korean galaxy s3 won't send sms with T mobile smsc

[Unregistered]

I have an unlocked Korean Galaxy s3 mini. I switched to family mobile thru walmart, which are both operated by Tmobile. I did a master reset and installed the correct apn and smsc as instructed by each provider. I have tried sms apps- hello, handcent, sms pro. All fail! I put my sim in another phone and i can send sms. I can receive sms, but I can not send. My phone worked perfectly in Korea with olleh, but in the US with Family mobile, operated by tmobile, it does not send out text messages. "failed" is the notification. I submitted a network tech ticket as well.

 

[B. Diddy]

Does it even make calls? Is it a genuine Samsung, or a knockoff/clone?