Disgusting mattress still under warranty

If I could give a zero-star rating, I would. We bought a Cloud Nine mattress for my parents in 2025. As usual, my parents use an electric blanket on the bed, and my mom reported the mattress smelled like coconut and got damp with the heat. Little did we know the damage that was actually happening inside the mattress, as this mattress is not heat resistant. The mattress no longer smells like coconut but is dirty from all the dampness. It is damaging the bedding and the base. It is unacceptable. The Bed Centre's after-sales service is absolutely poor, and we would not recommend this place at all. The mattress is still under warranty and does not say anything about not using an electric blanket. The mattress is standing against the wall as they refuse to sleep on something so disgusting. The Bed Centre refuses to replace the mattress and says the mattress is dirty and filthy. This indirectly states that my parents are filthy people. This is unacceptable. My mom gave my housekeeper their old mattress of 30 years, where they raised 2 kids, and gave it away with pride, neat and clean. My housekeeper stated in a video that it was still in good condition. The Bed Centre said that the supplier, Cloud Nine, says that something like that has never happened before, and they refuse to honor the warranty. The Bed Centre is selling mattresses of poor quality and provides unacceptable after-sales service. My mom went back and forth on emails, WhatsApp, and phone calls to resolve this matter, but to no avail. I am very disappointed that a business can stoop so low as to indirectly call someone filthy.