I used this website to unlock my LG G3 last week. Communication was excellent and I received a code in under 3 hours. There were a few issues with the process, first their website crashed after payment. I contacted their email and received confirmation that the order had gone through and an apology in a reasonable time.
When the codes arrived I was again a little confused as there were five codes, not one. Again I contacted them and they explained the NCK code was the one I should use and the others were only needed for other reasons by a small amount of phones, I won't go into the details lol as I still don't really get it!
My phones now unlocked and the first code did the trick. Good experience and they were very fast answering my questions and helping me through the whole process