From my searching, Samsung is nothing but a scam when it comes to this. You get an email 4 months later saying your phone didn't meet their expectations, like the screen was broken or there's water damage, and they charge your card automatically. People have to get the BBB and AG involved as well as report it to their CC company. Despite all this I still want to go through it because I won't get $300 for my phone any other way, I guess I'm stupid.
It also makes me not want to do business with Samsung in general though so we'll see. If I do go through with it, I will be taking photos and video of the phone being mint and everything working as I box it up.