Despite a 10-year warranty, the IKEA Kıvık seat cushion melted

Our Kıvık seat cushion melted, despite the fact that it was covered by IKEA's 10-year warranty, and this has been a major problem for us recently. After contacting IKEA's customer service, we learned that the seat did in fact have a 10-year warranty; however, we were not eligible for compensation due to "time-dependent deformation." We disagree with this position and think a warranty should be honored regardless of the effects of time on the product, especially when the buyer is promised a 10-year warranty. We would like an explanation for the denial of our warranty and are very dissatisfied with the service we received. To the extent that the warranty we were promised applies, we demand that IKEA investigate this and compensate us accordingly.