I am so sorry to hear your experience has been so unpleasant. As I have indicated in my previous post, LV hasn't been consistent when it comes to after care customer services at all. Since your boutique insists it's normal wear and tear (despite known cracking issues on PM), I would discuss with the store manager the fact that the bag they have returned to you has been altered without your permission (unauthorized changes/repairs on the flap) and, therefore, is no longer the bag you have submitted. SA calling this occurrence a “miscommunication“ is a simple case of poor customer service. Regardless of what one would call it, it isn’t going to bring you your bag back in its original shape and form with perfect patina. I would insist your boutique should rectify this situation and offer you a proper replacement due to unauthorized alteration of your item.
I also was able to find pic of my cracked PM and as you can see the crack was less noticeable than yours. This bag was purchased in Europe and was over 3 years old ,yet my local LV boutique in Canada offered an exchange on spot citing known issues with canvas PM.
I find this whole experience so frustrating on your behalf as it sounds like it’s been “paved” with total disregard and dismissal of your concerns

.