MacBook Pro Retina : the paint became matt where I rest my hand to write.

I bought 5 days ago a new MacBook Pro Retina 15" and I have used it in those last days to work.

This afeternoon I was looking at my notebook backlight and I saw that in the point where I rest my hand to write the paint became matt.

How is it possible that this kind of problem happen to a 2.300 Euros machine?

I'd like to ask to the Apple customer support to change my MacBook Pro with a new one where the paint was sprayed in a workmanlike.