My OnePlus Nord 3 Phone Stopped Fast Charging

I bought my OnePlus Nord 3 smartphone through Deichmann exactly one year ago with a 2-year KVK warranty. Now, my phone has stopped fast charging completely—it's barely charging at all! I've called OnePlus Turkey customer service (0850 390 1981) over ten times, desperately seeking support under the warranty provided by KVK and Genpa. Every single call ended with empty promises of getting back to me, yet here I am, still waiting after weeks of silence! No follow-ups, no solutions—just total abandonment. OnePlus Türkiye's customer service has left me helpless and frustrated. What's the point of offering a 2-year warranty if you won’t honor it when customers need it? OnePlus, I demand an immediate resolution—fix my Nord 3 or issue my refund (₺) now!