Audi Kept My Q7 for 15 Days Did Nothing and Unnecessarily Replaced My Battery

I took my Audi Q7 to the authorized service, where it stayed for 15 days without any repairs being done. After pointless delays, they claimed I needed ₺700,000 in repairs due to black smoke coming from the engine. Then they admitted their mistake and said they would replace my battery. They replaced my one-year-old battery, took the old one, and later refused to return it with various excuses. When I told them the issues persisted despite the battery change, I received no response. To make matters worse, they never properly diagnosed the actual problem with the car. They charged me ₺18,475 just for a battery replacement. Audi’s authorized service lacks both technical knowledge and competent staff.