Varta Battery Complaint and Warranty Hassles

I purchased a Varta Battery from N11. About a month later, the battery stopped working. Due to my busy schedule and having a second vehicle, I couldn't attend to it immediately. When I finally reached out to the seller, I was told to go to an authorized service center with the warranty document. However, the battery I received didn't come with a warranty document. Initially, I didn't think much of it since the product came with a receipt, but when the battery malfunctioned, the situation changed. I struggled to reach Karat Power, the importer mentioned on the receipt. They informed me that they couldn't assist me because the serial number of the battery was missing on the receipt. After adding the serial number to the receipt through the seller, I still couldn't reach the importer. They neither answer calls nor respond to emails. Order date: 01/01/2024 12:30, order code: 201967297315, amount paid: ₺3,049.99, address: Osmangazi. Product: Varta Battery g8 12v 95 amp 830 aen reverse pole, March 2023.