Ball Joint problems of the 2015 Jeep Wrangler

At 34,000 miles I started to experience a rotational vibration in the front end of my vehicle and the drivers front suspension started to get louder over a couple weeks so I took the car to a dealership, they diagnosed it as the ball joints were worn and they said it was still loud due to tires age (which were rotated with every oil change at approx 4,000 miles). The tires were not worn due to age but instead cupped due to damaged suspension component, the dealership that I had the vehicle serviced at on 12/15/2016 at 32,534 miles found the tread depth to be at 8/32 or greater. I took the vehicle in a few days later back to the dealership that did the repair and they found the tread depth to be at 9/32.