I'm sorry I can't offer more, we've escalated to our promotions team about it previously and the response we got back was: "We don’t have insight into any of their Epic Games accounts and we have no tools available to pull strings or fix any issues that they’ve encountered."
That's fair. There isn't much any of the mods can do on the forums except pass messages along, but you would think that if Samsung's promotions team is being flooded with tickets and requests about galaxy skins not being received, they would light a fire under Epic and tell them to get their act together. Their name is on this promo also.
Here's how I got my free skin: I created a fortnite account on my PC(registered for android platform). Registered my Note 9 on my Samsung website account on my PC. I added my Samsung account on the Note 9 by loggin in. I then downloaded and installed Fortnite from the Samsung Galaxy App. I played 3 games. Exiting to Lobby after each game. Around 24 hours later I went back in the game and the skin was there. I didn't get any emails.