Black Streaks on Deichmann Shoes

I recently noticed that the cream-colored shoes I purchased from Deichmann developed black streaks on the inside due to the black strip along the inner sole. These marks have caused significant discomfort in terms of both appearance and usability. I submitted the product to your team for inspection under warranty. However, I was informed that “no manufacturing defect was found.” When I spoke with your customer service, I was told that the formation of such stains was deemed “not possible by experts.” Still, this issue clearly results from the product’s own material and cannot be explained as user error. As a consumer, it is unacceptable for my complaint to be ignored, no responsibility to be taken, and no solution to be offered. Considering the product reached this condition in such a short time, treating it as normal is surprising. I kindly request a product exchange, refund, or at the very least, a repair. Otherwise, I will file a complaint with the Consumer Arbitration Board. I submit this for your attention and ask for my issue to be resolved as soon as possible.