with your computer in one hand and a two-by-four in the other, they'll fix it right away
I sent in my MacBook on Tuesday to get new panels after discolouration. On Thursday I received a call saying it was ready and so I picked it up, it looks great now although the main button is soft, not the hard click it used to be. The plastic is definitely harder and a darker grey. Replaced trackpad too, btw.
Upon bringing it home, it started up but the iSight was on permanently, which is strange. I opened Photo Booth and the image was just a green screen, even after a photo & effects. Following that I restarted the machine and it stared back at me with a blank grey screen.