Apple MacBook Pro Won't Turn On, Warranty Denied Saying It Got Wet

I bought a MacBook Pro from Apple last year for 31999₺ and it's still under warranty. Last week, my computer wouldn't turn on, so I thought the battery might be dead and plugged it in to charge. When I got home that evening, it still wouldn't turn on. I tried using my brother's charger, but it still didn't charge. I scheduled an appointment with Apple and took it in the next day. They mentioned it might be a software issue and presented me with a bill for 17,000₺. However, they assured me that I wouldn't have to pay because it was still under warranty. Today, they called and said liquid had entered the device, causing corrosion, and that it's now out of warranty. They even mentioned I'd have to pay 38000₺ for repairs. I'm furious! I never spilled any liquid on it or did anything to damage it. My computer has become useless! I urgently need Apple to resolve this issue!