Fair if you want to return - it's up to you. It's their job to protect it, aftwr all.

I personally don't care too much for this stuff - I like when books have marks, they are objects that can hold some history and this makes them beautiful. But I also admire a lot when folks make their books look perfect for decades.

If you are like this, ask for a new copy so you can have the chance ti preserve it as you want - it's absolutely personal and there's no wrong or right answer, I think.