The driver's seat on my 2015 Silverado is loose as well. Brought the truck to AutoNation of Pembroke Pines for warranty repair three times. They never even ordered the parts for the repair as confirmed by Chevrolet Customer Service. Only positive measure they took was to use a plastic tie strap to secure the seat frame, which did nothing to remedy the situation.
After months of dealing with Autonation Chevrolet and the truck now out of warranty I contacted Chevrolet Customer Care. The rep there bent over backwards trying to get my truck fixed at another dealership as I explained to her that I was not willing to waste one more day at AutoNation Chevrolet of Pembroke Pines, even though they now were willing to order the parts and do the repair after being contacted by corporate.
Unfortunately she was overruled by a Chevrolet regional manager who insisted I go back to AutoNation regardless of me having wasted many hours and days there. Now I have a truck out of warranty with a loose driver's seat.
Stay away from this dealership and Chevrolet altogether if possible. The dealer doesn't repair the vehicles as required, and Chevrolet is unwilling to have my truck properly repaired elsewhere. I've owned four GM trucks. One Certified Pre-owned, one used, and two new ones. Truly did not expect this from Chevy but I guess times are changing and business is now being done for the short term.
Buyers beware.