I've had iPhones, Sony and Samsung Android phones unlocked for me by Cellunlocker.net and the latest one was an LG G4. I think I made a mistake with the country of the provider of the LG and Cellunlocker assured me that the codes would work, and that if it didn't, gave me instructions on what to do. But I never had to worry coz the first code they gave me worked right off the bat!
They have been consistent with giving their correct unlock codes and have very good customer service. Well done, Cellunlocker.net!