my sons phone is locked and we do not know the pin HELP!!!!

OK this is what happened, Sprint is upgrading the 4g out here, and the store reset the antenna settings in hands free mode. now it is saying that the phone is lost or stolen it is a S3, I do not know the pin I tried the pin I thought it was and even 0000, I even sent it sms from my phone ( it received them) to unlock it didn`t work, The phone is not listed under my email address, and i cannot figure out what it is. and my 12yr old is suffering from withdrawal from you tube. HELP