Without seeing the dot from distance I can't say how bad it is
I'm usually happy with bags I get and most of the time when I look at "defects" or "is it normal" threads...those "defects" are pretty normal to me.
However, I have a pink lamb rectangular mini and the first one from store came with a very tiny blue pen mark. At first I thought it was dot but I can't wipe it off. I'm usually bad about noticing these things BUT on light color bags they can be extremely obvious. So store shipped me a replacement and I returned the first one. And I can totally relate to you.
I know lots of TPFers love her. Personally I never have good responses from this famous PS on IG for items I ask her to look and I'm sorry this happened to you.
Last time I used a PS it was with a Celine nano. It came with store defect and this very PS (not the same you dealt with) was able to send it back to Celine Germany as its defect.
So I don't buy that "France custom" and "in Europe we don't do this" crap!!!!
But this is really true! SAs can get really sticky in Europe and also Asia and Australia on return polices. Consumers in these countries simply don't have the clout of US customers when it comes to return and exchanges.
Complaining to management hardly works as they hold the same stance, no returns and exchanges, unless absolutely necessary.
The seller could put it across more politely though.