Faulty Aeroccino

I bought a Aeroccino milk frother from Nespresso a couple of years ago and not long after I had the machine milk started sticking and burning just behind the stand for the whisk. I mentioned it to a shop assistant and she said it couldn't possibly be a fault it must have been scoured, but I can take it in and they will give me 50% off a new one... I know it was not scoured as I am the one who cleans it and very well after each use. Over the last year my machine has gotten worse and now the burn mark is there permanently. I decided to google a solution and was I surprised to see that exactly the same fault is happening to a lot of people from Australia to the United States. These complaints are dating back to 2010 and from images I have seen its in exactly the same place each time. I ask you Nespresso, are you SURE it's not a manufacturing fault and why are these faulty machines still for sale?