Last year I purchased a Silca Locking Presta Valve Chuck (Hiro) after reading reviews here on slow twitch (I can't recall where I purchased it from).

Fast forward to this year, and the wavy washer on it breaks.

May 21 - I fill out their "Contact Us" form on the website, explaining the problem, and requested a replacement washer.

May 22 - receive a personal follow-up email the following day, and was told they would ship me a whole new chuck.

May 31 - the replacement chuck shows up in the mail (in Canada).

I have no connection to Silca, I'm just super impressed when a problem with a product is resolved so quickly and with so little effort on my part.