Quality Control deficient

The screen looks very good and also has a beautiful image, in the quality control has been in my opinion but sloppy.
Now I have already provided to the third screen at me. The following issues have led to the exchange:

1. Screen: The display was peppered with pixel errors, many are constantly lit, some black
2. Screen: A small gray spot (about 2x2 pixels in size) by the backlight, and what was worse, he had not power with plugged Mini DisplayPort cable.
3. Screen: Several gray dots and two black pixels (quite possible that I find here more, since I do not yet have the third time)

The support is indeed great and the exchange is not complicated, though it all costs time.
For the price of the monitor I had just expected better quality.