Torn Adidas Shoe Lining Complaint - Warranty Denied

I recently purchased a pair of adidas shoes, and to my disappointment, the heel lining unexpectedly tore after only a few months of use. I returned them to the store for warranty inspection, only to be informed that the issue was due to my own mistake. I reject this explanation. According to your website, the warranty covers any damage to the heel lining. I'm extremely let down by this reply. When you invest a significant amount of money in a product, you rightfully expect superior quality and service in return.