Hardware quality issue
My 13 inch macbook pro (late 2013 haswell) keyboard's black color is fading out on the spacebar and now there's a white patch on it and growing. Also the aluminium body is suddenly getting somehow "corroded" by itself and that patch is getting bigger and bigger near the trackpad. It is concerning the quality of the build materials used. I use damp cloth to clean the macbook. I have registered the problem at the Apple service center but they did not turn up . It has been more than two weeks since I've reported it to them. Please guide me.
MacBook Pro with Retina display, OS X Mavericks (10.9.5)