JBL 560BT Headphones Battery Failure and Warranty Woes

In October 2021, I purchased JBL 560BT headphones. Apart from the leather parts peeling off, there were no issues, so I tolerated it and continued using them. However, last month, the headphones stopped charging and working altogether. Despite many private services claiming they could fix it, even suggesting a more powerful battery for extended use, I opted for the authorized service, Aztek Teknoloji. Aztek Teknoloji informed me of a battery problem and stated they couldn't replace it. Instead, they offered to sell me the same product at a slight discount. They demanded ₺1521 from me. Firstly, they claim they can't replace the battery because it's not available, even though the product is still being sold. Would they refuse to replace it if it were a new product with a warranty? A product must have spare parts available for at least ten years, which is a violation of consumer rights. This product's warranty has just expired. The discounted price they offered (₺1521) is above market rates, presented as if it were a favor. I paid for the shipping when sending the product, which is fine. However, they burdened me with the return shipping for a product they couldn't fix or stand behind. Once I receive the product, I will escalate the matter to the appropriate authorities. I don't recommend Aztek Teknoloji, though not the brand itself.