I brought a flat tire in to them for repair this week and they fixed it, no charge. This wasn't a tire I purchased from them - when I asked about the cost as he was loading the tire into my trunk, the sales rep just said, "Oh, we don't charge for flats."
I don't know if that's because I removed the tire/wheel from my vehicle at home and brought it in or if they would do the same thing on the car.
I didn't time my pit stop at home to change the tire, but I did feel better about not driving the car to the tire store on a stupid run-flat tire.