BMW 320 Diesel xDrive Plastic Deterioration Under Windshield

I own a BMW 320 diesel xDrive, and about a month ago, I noticed that the plastic part under the front windshield had started to rot. Since then, the condition has worsened, and the plastic now looks worn and damaged in a way that I do not find acceptable for this class of vehicle. I went to the Kosifler service center in Samsun, where I live, and they examined the part and stated that it needed to be replaced. I was informed that the cost of this replacement would be around 6,k, and that it would be a paid process.

This part has never been replaced before, either under warranty or as a paid repair. I believe the rotting of the plastic under the windshield is not a user-related issue but a material or production quality defect, and I find it disappointing that such a component deteriorates in this way.

I request that this part be replaced free of charge as a gesture of goodwill and customer satisfaction, and that the necessary support be provided to resolve this issue without cost to me.