Apple thunderbolt quality and service

Hello everyone.

First of all - sorry for my english, i am not a native speaker.

Right now my Thunderbolt display in service about a month, my case number 1000318945.

So, the story is - i discovered dirt under glass of display, so i called to Apple, they say - come to service and we will fix it for free.

In service new display block was installed, with horrible blacklight.

As you ca see, bottom left corner is highlighted badly.

After that it was to weeks of diagnostic they installed another matrix. With the same issue.

I also discovered scratches on my display.

So, right now it is another week of diagnostic. Apple support can't do nothing.

Is there anything i can do in that situation? Need advice.