No written order given. Window installed

Most stupid reactions come from stupid announcements or actions.
In this respect, one should first examine oneself whether the "tone" of one's own behavior is justified.
I find the headline here quite specific and statements like "was even delivered incorrectly" ... and I hope that words like nonsense were not "thrown" at the contracting partner, as happens here in the forum.

No, it is clear that tone makes the music. Delivered incorrectly, since we actually ordered a different sliding element and now received another one, and moreover with scratches and very poorly installed.

The scratches always seem to have the same pattern, just weakened downwards. Have you ever checked if these are deposits that can be wiped off?

Unfortunately, they cannot be wiped off.

Otherwise, the formal way with a notice of defects is the best way – have you already paid?

There are 3 similar occurrences of this. but let's wait and see if the friendly Florian can polish this away :)

I actually see even more: [ATTACH alt="E38FC7DF-6BB7-4F1C-A140-213729C7AB67.jpeg"]57726[/ATTACH][ATTACH alt="23B4383F-99C9-45C0-9C62-CADF05D89E11.jpeg"]57727[/ATTACH] I wouldn’t like that either. These are clearly damages. Next time please take photos with a scale. However, it’s always the tone that makes the music. And the formality of the reprimand.

As ypg already wrote. Create a notice of defects with a deadline for elimination.

Can you at least prove exactly what you ordered?

Is there a protocol for the final order? Or an order confirmation?

Could the black scratches also originate from incorrect operation or be contamination?

Did you raise the defects when they were still on site? Otherwise, everyone shifts the blame to the other subcontractor.

Refuse acceptance until the defect is remedied. Retain part of the outstanding invoice amount.

Oral communication is possible too. But then you don't have anything in your hand. At least you should have a negotiation protocol.

No phone! Always in writing.