I purchased a Philips LED GU10 (track lighting style socket) bulb in March 2013 to replace crappy halogen ones and finally this past week one of the 5 light bulbs quit working.
These were $30/bulb when I bought them in 2013 so I saved one of two of the cardboard boxes and my receipt and just had it sitting in the bottom of my light bulb drawer. These had a 6 year warranty so I emailed Philips on their support site within a few hours they followed up asking me for a bit more information (pictures of the receipt, bulb model/upc, what fixture it’s used in, etc.)
I emailed them back with 95% of what they asked for and I got a reply within a day or two saying they will send me a check for the purchase price. With today’s LED prices I can buy 6 replacement bulbs for that same price so needless to say i’m pleased with their resolution.