Has anybody activated the Samung Galaxy S 4 Unlocked International Version. It seems that my phone keeps saying "no service" with an active SIM card installed. How do I fix this problem? NET10 suggested that the SIM Card was locked but this phone only comes in the unlocked version and I verified the the IMEI is good too. So I am not sure what is going on! Any help on getting these up and running in the US!?