ᐅ New plastic front door warped

Hello!
In November 2021, I had a new plastic front door installed with a glass section.
For some time now, the door has become difficult to unlock. Locking worked normally, but it reached a point where the door could no longer be unlocked at all.
I reported the problem to the installation company. They found that the door had warped. The explanation was that the new door is so heavy that it has sagged towards the lock. This made it difficult to unlock the door again. Adjustments were then made to the door hinges. This (initially) solved the problem. You could clearly see that the upper hinge had warped. After the adjustment, the door can be locked and unlocked normally again. However, one of the hinge guides already has a crack. Despite the adjustment, the door is still warped and no longer horizontal (see photo).
My questions:

• Is this normal?
• Are there any warranty claims in this case?
• How should I proceed?

1. No, that is not normal.
2. Yes, the company did try to pass the blame to you (you chose it yourself, too heavy, state of the art).
3. File a complaint.