Plastering work in new construction was poorly done, any experiences?

Hello everyone! Our stairwell, as well as some of our room and exterior walls, are in my opinion very poorly plastered (see pictures). However, our construction company denies this. Could you please provide an assessment based on the pictures? How would you behave towards the construction company?

Hard to see on the phone. Just looks blotchy - was it painted over?

I know it is difficult to see. Yes, the painter from the construction company was there and painted again. He left the house saying, there's nothing more I can do if it is plastered so poorly.

Looks "wavy" in the pictures. Are those brick walls or wood studs covered with drywall?

What quality was agreed upon?

I would say: It is not nice but also not a defect. No chance to get anything through here. [Streiflicht] is also not allowed for defect assessment. At least two pictures are in [Streiflicht].