Columbia Ekru Outdoor Shoes Stitching Came Apart After 8 Months And Warranty Denied

I purchased the Columbia Ekru Outdoor model shoes through Boyner. About eight months after purchase, the stitching on the shoes started coming apart. Since the product was still under warranty, I applied for warranty service through the Boyner store. However, after inspection, I was informed that the issue was not caused by a production or material defect, and my request was rejected. I also contacted Boyner customer service, but the product was returned to me on August 31.

My warranty and invoice period are still valid. I do not believe the stitching defect was caused by user error, and I am requesting that the product be replaced. I kindly ask for my grievance to be resolved.