Somebody asked me about this. They found an iPhone 6 and they wanted to reactivate it. So I went searching. I found nothing but scams and people trying to make money on this. Be careful. And Welcome to MDL.
How can the service "whitelist IMEI", IMEI is managed at carrier level, unless the service has access to all carriers lists around the world it is impossible. Did they keep your money after reply? How much was it? Were they attempting to remove the device from another owner's apple ID without his permission? Does not seem possible.
They wrote: So they did not give me cash back but I can unlock another device instead. I do not know how they do the unlock thing but I was watching the progress on the order and every day the percentage changed, 20% done, 25% done etc. But yeah they remove the device from the iCloud account so it's not locked to it anymore. It was a phone from a guy who's daughter has died so he wanted to use her phone and I did not check it if was reported stolen, it makes no sense that she reported it stolen right before she died. He could not find any receipt so he can't contact Apple to unlock it, probably she bought it used and didn't receive receipt.
What if the guy with the device in his iCloud notice it disappear, and complain to apple? Will it relock the phone to his iCloud? You said a site confirmed it was stolen phone but it made no sense she reported it, what if the service you paid for reported it stolen and used it as an excuse to keep your money without unlocking it?
I dont trust services like this, its not even official apple unlocking so i always ask my self ... how can they access their cloud service to unlock stuff ?