Purchased a Dyson purifier hot and cold formaldehyde on Amazon. It stopped working just after the Amazon 6 months cover. so i contatced Dyson and had to provide proof or purchase etc which i did. Dyson refuse to repair it despite it being registered with the warranty via their app. they are saying the serial number is incorrect. If it is why does the Dyson app recognise it. It is clearly a dyson and i sent them a picture of it. so i have a very expensive Dyson machine that is not working. they did say i could take it to a Dyson shop -465 miles away!!