Asus Laptop Malfunction: Constant Shutdowns and Warranty Denial

Hello, my computer automatically shuts down when I start it. It stays on for about 1 minute and then shuts down immediately. The battery never goes above 5%. When I contacted Asus Turkey to report my issue, they demanded a technical service fee of 450 TL, even though my warranty is still valid. As far as I know, no payment should be required under warranty coverage. I urgently need a new battery. Can you please assist me with this matter? Facing this issue has been incredibly frustrating, especially when my laptop is well within the warranty period. The automatic shutdowns and inability to charge properly have disrupted my work and daily life. I hope Asus can resolve this matter promptly, as I rely on my laptop for various tasks.