About 2 years ago I bought a Petzl Myo XP from Needlesports and it's done everything I've asked it to from 06:00 walk ins in Scotland in winter to talking the dog out into the garden (more of the latter than the former though!). A couple of weeks ago it flickered a few times, worked intermittently for about 5 minutes and then stopped working all together. Petzl provide a 3 year guarantee from the date of purchase so I contacted Lyon equipment directly as I didn't know off the top of my head if I still had a receipt from Needlesports, they said that without knowing the date of purchase they guarantee from the date of manufacture which is stamped on the torch. Sod's law meant that it was manufactured just over 3 years ago so I told them this, said thank you for their help and that I'd start looking for the receipt, their response was "send it to us and we'll see what we can do". In the meantime I'd found the order confirmation email from Needlesports (one major advantage of online ordering!) and posted the headtorch off to them.
This morning I had a shiny new head torch delivered to me in the post and it's the next model up, the Myo RXP, this has made my day so a big thumbs up to Lyon equipment, Needlesports and Petzl. I highly recommend them.
tldr: headtorch broke, replaced with upgrade, happy days.