Yellow:

I had a new pair of Trek Crit shorts fail on me recently. The stitching that held the pad in place broke. I contacted the LBS where I purchased them but because they had been worn they would not exchange them. I then contacted Trek directly via email. I explained that I had, like you, rotated these shorts, that they were only 8 weeks old, had minimual miles on them, etc and asked if this was normal for their shorts. I received a very quick reply of no this was not normal and they would gladly replace them if I sent the shorts and receipt to them. I, of course, no longer had the receipt but the store kindly reprinted me a duplicate one. I sent the defective shorts and receipt off and within a week received a pair of Nike shorts in the mail. I love these new shorts, much nicer than the ones I returned. It was nice to know that the company stands behind their goods and more importantly values me as a customer. If the LBS won't work with you contact the company directly and explain the situation, I bet they will work you just as Trek worked with me on my issue.

Good luck!