Macbook Pro Retina Display Pixel / Dust Scratch problem

I have a MBP 15' Retina purchased in October 2012 and last night noticed a number of small white dots on the screen which appeared to be dead pixels, booked into the genius bar this morning and was told that the dead pixels were actually dust scratches where a small piece of dust had got caught between the screen and keyboard when it was closed and had damaged the screen. You can feel tiny bumps if you run your finger nail over the areas so this may be the case but while it may be the reason you'd expect that a $3500 machine wouldn't have a design fault that allows tiny dust particles to damage the screen.

The Genius said that this was a known issue and that while it had been escalated with other customers' machines, the issue is cosmetic and not covered under warranty.

Has anyone else had this issue and what were the /are the steps to getting the screen replaced under warranty given that this apprears to be a known isssue and shouldn't happen to a $3500 computer.

Thanks