BMW IX40 Battery Problem

I bought my BMW IX40 electric car in November 2022 from the Ozgörkey Izmir dealership. I was happy with the car, so I decided to buy my second one, the BMW IX50 Electric, from the Kosifler Istanbul dealership on October 9, 2023. Yesterday, around 5:00 PM, I couldn't open the car doors when I tried to get in. I need help with my BMW. A technician told me that the 12V battery was dead, so they charged it and suggested that I take the car to the service center. I left at around 6:10 PM, but at 6:30 PM, we got a warning about an electrical problem, so we had to call for help once more. The technician did the same thing again, but the problem didn't go away, so we went to the Ozgörkey Izmir service center. Even though I explained the problem to the authorities, they said it was my fault and wouldn't fix it for free. After trying many times to fix the problem without any success, they suggested either returning the car or buying a new battery. Even though it was my second car and I had negotiated for a third car (I have emails as proof), this problem has made me lose interest in the brand. The dealership and the brand's response has been really disappointing, and it's making me think about taking legal action if they don't give me a solution.