Kolombiya Shoe Foam Deterioration and Discomfort

I purchased a Kolombiya left shoe and experienced an issue where the foam has deteriorated, causing a part of the shoe to sink. This resulted in discomfort and injury to my foot, particularly at the bottom near the arch. I reported this issue to the store where I bought the shoes, requesting a replacement. However, the store claimed that the problem is not due to a manufacturing defect and insisted that my issue was not covered under their warranty. It's worth noting that the right shoe is in good condition, but the foam in the left shoe has deteriorated, causing discomfort and injury. The store has attributed the issue to factors other than a defect in manufacturing.