Disappointment with Service Received from BMW Joburg South Dealership

I am extremely disappointed by the BMW Jounurg South dealership with their service. I booked my car in their dealer to replace the battery on my BMW 320i last month on the 26 May 2025. The lady who was my service advisor gave me a wrong report, stating that the battery is still fine and they charge it, assuring it will never give me problems again. Despite my numerous complaints about the battery being flat and my maintenance plan expiring on the 28th of May, she insisted the battery was still fine. Now, the battery is causing issues again, and my motor plan has expired. I am very disappointed with BMW. As a loyal customer, the way I was treated has made me reconsider purchasing another BMW model.