Tina, I am so very sorry to hear of the craftsmanship issue on your Sellier Birkin
I once had to accept a boutique credit for a leather quality issue. It is so disappointing because we want the bag, not a credit in lieu of the bag. In my case, it was two years before they were able to source a specific bag I wanted, and by that time the bag price had increased, which diminished the relative value of the credit.
Since your situation was recent, I’d suggest you politely yet firmly communicate to your SA—or speak directly to the SM—that you’d like the same color and style bag you originally had. The longer it takes to use your credit, the higher the price will be for the identical bag—due to price increases. That was the lesson I learned from my situation. In my case, I couldn’t accomplish an exact replacement bag because Hermès had taken the color out of production.
What color was your returned Sellier Birkin? I know you said you loved the color, but I couldn’t quite tell from your photo. I do hope you end up with an acceptable bag offer to allow you to use your credit before the color and/or the pricing changes.