I'm sorry to hear about your experience. Because of our high rate of fraud and gray market sales, we do require a receipt for warranty replacements. Product registration is not the same.
Please keep in mind Klipsch is a relatively small company, and we simply cannot absorb losses like I'm sure Apple and Kenwood can. One set of headphones would obviously not break the bank, but if bent the rules for one person, we would have to for everyone...then there would be no point in having the policies. It is in place not only to protect us, but consumers as well.
That said, there is no excuse for you to be treated rudely. I apologize for that, and will point this out to our customer service department.
Can I ask what happened to your X10s, and how long did you have them?