Fakir Judi Black Electric Kettle Leaking Water From the Bottom

Hello, about two years ago, I bought a Fakir Judi model black electric kettle online. Yesterday, I noticed that it was leaking water from the bottom. I took it to the Fakir service in Ankara Balgat Çağrı Teknik. They said they would check it under warranty if I had the receipt. Unfortunately, I didn't keep the receipt as I trusted the brand. They informed me that the diagnostic fee was ₺50, and if I decide not to proceed with the repair after they check the device, I would still have to pay ₺50. I reluctantly agreed. In the evening, they called me and said the interior and gasket of the kettle needed to be replaced, and it would cost ₺400. Now, I ask: 1. Is it fair to charge such a high amount from the customer for a water leakage issue that seems to be a manufacturing defect? (I read complaints on this site about similar issues with new models) 2. Is it legal and ethical to demand ₺50 under the name of diagnostic fee? I'll wait and see if this reliable brand will address the issue. Good evening.