There is no SAMSUNG A979...That is SAMSUNG Flight A797 ...You can get the Unlock code from the site Onlinegsmunlock.com/unlock-your-phone/rs7wp2/ and Unlock it from network lock....
There is many free samsung flight a797 unlock code from internet, but almost of them is a fake code and can't unlock your phone. But if you still want to looking free samsung unlock code try in this link. Go to free unlock code section in right menu header. Good luck!
SafeLink usually allows one free cell replacement. After that you can buy them from their affiliate store or any other place you choose. Just make sure it's compatible with their service if you choose to go elsewhere.