Digitizer cracked with no shock or dropping but not screen (glass)

The first I noticed an issue was when a small 'crack' appeared in the displayed image of my MacbookPro.

There had been no physical damage or trauma to the laptop whatsoever.

There was no exposure to drastic temperature change, nor extreme temperatures, as this was a laptop that lived on my desk at home, my desk at work, in my bag on my passenger seat of my car, (NO it never jumped off the seat because I had to slam on the brakes or anything like that).

It has been well cared for.

There was no crack in the glass, nor any disruption of any sort to the black edge around the actual digitizer display screen under the protective outer layer of glass.

I brought the Macbook into the Apple store with no luck as they told me all about how a service plan had not been purchased with it and that even if it was a manufacturing or part defect, I would still have to have purchased the extended service plan for the laptop even though I had not even had it for a year at that time.

So I've been running this laptop for about a year now, not taking it anywhere, not moving it, not running it for any extended amount of time.

I can't.

The crack in the digitizer has since moved it's way around the screen and made the display on the Macbook completely useless.

I have an HDMI cable connected up to a TV that I am using as the monitor.

I have not opened the case. I have not removed any screws.

I have not done anything that would void any warranty or broken any interior seals or the like.

The last time the interior of this laptop has seen anything other than itself was at the factory when it was manufactured.

Today when I got home from work, I noticed two marks on the lower left corner of the screen.

One is below the surface of the glass.

The other appears to be either a burn or some sort of chemical reaction that has 'eaten' through the outer glass.

No one even comes into the room where this laptop is other than myself.

Whenever I am not using the laptop, and sometimes even when I am, I disconnect the magnetic power cord as to not leave it charging constantly.

Coincidentally, this happens to be the same corner where the initial split in the digitizer originated from.

I'm not sure how this is not the ultimate manifestation of some sort of manufacturing or part defect and how do I get this fixed without having to pay money for something that has never been my fault, nor something I should have to pay for.