unlock my phone iPhone 4S

Hello, I am a user has come from China.I commissioned my friend to travel in the United States when, in your company to buy iphone4s.Can not use the machine back to China, I was very depressed.I heard that to unlock the fight customer service calls, but my English is poor, unable to verbal communication.That I issued the contents of this email is to use Google Translate to write.Please help me with this Apple fans, please help my broken heart I do not want to see all the way no contract cell phone bought from the United States can not use, please help me unlock my iphone4s permanent.Thank you, good turn deserves another.I iphone4s the MEID: 99000107961391. God bless you happiness and peace.