I was impressed by the amount of positive follow-up by Cellunlocker when I expressed a problem starting up my new phone - it was not related to the unlock code provided by this company. Eventually the matter was fixed by the phone seller and the unlock code worked perfectly the first time. I would definitely use them again.
Tip for consumers: There seems to be a few scammers out there offering "free" or very cheap phone unlocking, but Cellunlocker is not one of them.