How to block new unopened IPhone and add in black list if it’s been stolen I have IMEI and receipts

That's something you need to file a police report about. You can't block an unlocked, never set up iPhone. Sorry you were ripped off, but that's outside the scope of this forum. Apple never gets involved in lost or stolen devices. Contact the local authorities.

You can't.

Report it to the police. Apple can't help you.

Similarly “blacklisting” is something performed by your carrier …

… but since the phone was never part of your account on your carrier’s network, they can’t blacklist it.

Atanasov33 wrote:

I am already reported and get NFRC number

OK. Good that you reported it. But that won't stop whoever ripped you off from using or selling the phone. Face it, you got ripped off. You lost your money and there's nothing anyone here nor at Apple can do to help you. The police advise for transactions like this, you should instruct the buyers to meet you at a police station. People are not too likely to rip you off in the presence of authorities. If you trusted someone and you shipped the phone off, well, that just wan't wise to begin with.

OK... that means absolutely nothing.

You can't block the device or have it blacklisted.

There is absolutely nothing you can do about it.