If you had seen the bottom of the pochette at the boutique would you have left with it? I the answer is yes, then keep it. If the answer is no, then return it. I now look over any new purchase to make sure I like the bag/slg before buying, and that includes wonky stitching and clean glazing and perfectly working closures and reasonably unscratched hardware. As I've said before, some SA's get annoyed and I've had one walk away from me while I did it, but I couldn't care less. They aren't the ones buying the bag, I am.
I would not have left the boutique with that bag due to the stitching because it would bother me. Might not bother someone else.
But since you have the bag at home now, I'd consider the advice of the heat, stuffing the bag with tissue, etc. If it looks great after that, then keep. If it's still puckered and wonky, then be sure to return it before it's too late. And try not to get caught up in the scarcity hype. Easy come, easy go. There is alway a new bag on the horizon.