Zara Jeans Ruined After One Wash

I recently purchased a pair of jeans from Zara and was dismayed to discover that they became discolored after just one wash. Despite following the care instructions and washing them on a low temperature cycle with similar colors, a straight white line appeared across the entire length of the jeans. I attempted to remove the stain by ironing, but to no avail.

The absence of any "dry clean only" instructions on the garment further adds to my frustration. I am deeply disappointed with the poor quality of these jeans and the lack of clear care instructions provided by Zara.