The serial number you originally posted was of a phone that was returned to Apple under warranty and was replaced.
When Apple gets those phones back they are either recycled or are remanufactured into new phones, and those new phones receive an all new serial number.
It appears that phone disappeared somewhere between Apple and the recycler and was resold to you, unfortunately.
It’s unclear if you are still referring to that same phone or not.
If it was a phone that was to be recycled, Apple will not activate it for use on any carrier.
As I am just an Apple user like yourself, I can’t give you any more advice other than my previous advice to try and get a refund from the seller.
Alternatively, you should contact Apple Support directly as directed at the link and ask if they can offer any solutions:
Contact Apple for support and service - Apple Support