It's all over their web site. Lawyer up.

I purchased a set of their Transit Epic Panniers just days before a week long tour. Well I didn't figure out until we started the ride that they sold me two of the same side and it was too late to take them back at that point so I did the tour with it that way which resulted in heel rub on one of the bags pretty bad. At the end of the tour I took them back to Performance and the guy started giving me a hard time...they have way more than 5 days on them (no they didn't) yada yada yada. I said "You have a 100% satisfaction guaranteed return policy right?" The guy said "Yes but..." I said then I need to talk to your manager. At which point he swapped one of them out for the correct matching bag.

I'm not saying it would be morally correct to do it in this situation...but one of my friends and the GM of my LBS used to be a manager at a Performance store in DC. He said people would buy shorts...wear them out and then return them and they would refund their money or credit them just like the policy states.