Those scratches will polish out since you got the silver, uncoated stainless. I'm sure there are threads that tell you which metal polish to buy and how to do it.
I try to avoid these types of issues by never letting Apple employees touch my phone. I just had to get a replacement for my Pro Max and the Apple Store employee whipped out a new box and started ripping it open before I told him to hold his horses, and that I don't need assistance unboxing and turning on the new phone lol. I really wish employees would ask before doing that. When I bought an $1800 TV from Fry's, I learned after purchasing, as I was walking out the door, that it's their required policy that every TV be visually inspected for scratches and to make sure it turns on before it leaves the store. Just what I want... to unbox my $1800 TV in some filthy store. Yeah, never buying a TV from Fry's again.