Big Costco Fan
Though I haven't bought any tires, I will say that having dealt with several issues with Costco, each time I have been COMPLETELY satisfied with their customer service as well as "attitude" of all employees. If you've got tire problems, get to the regional office (thats the power center) you WILL get results.
BIG difference from the other warehouse club that I (s)am a member of - where employees "just don't get it", that is, when you can find them. Tried to special order a 6V battery there and was frustrated by all employees at all 3 area clubs -they didn't even know how to order a battery - believe me, when I got to management in AR, the s*** hit the fan, and I got my battery, but at that point, it was about my ego, not the battery.