Lacquer peels off

Yesterday the big laundry after the winter and when the leather is removed suddenly the paint on the threshold (driver’s door) peels off. Of course it looks like so, so whether we have stayed permanently with our shoes on it. But that is definitely not the case. We are sneaker carriers and also still articulated. Has also only 13 TKM run. Such a thing must not be. Now also the second horror, the VW dealer says that it is our fault and a guarantee performance probably not be The only reason I can think of is that last year the driver’s door was set up. Maybe the paint was damaged. But the dealer says that it can’t be. Nothing can have been done from the outside, since the door can’t be reached. Do you have an idea (or at least comforting words)? I have attached pictures.