Shower cabin poorly installed

Hello everyone, as a precaution I have adapted my bathroom to be accessible for disabled people, you never know what might come, i.e., barrier-free, with a new large whirlpool bathtub and a new shower. The bathtub is very good and works just as I imagined, I installed it myself. Only the shower. It is a Kermi shower enclosure, semicircular on a straight wall, both glass doors open to the right and left. The installation was outsourced by the seller, a large sanitary retailer in Bavaria, to an external installation company. First, after setting the shower tray, everything was measured extensively. Then it took a long time before someone came and installed the enclosure. That was the aforementioned external company. This company completely botched the installation of the enclosure so that water leaked out on the sides, one side was installed so crookedly that there was a gap several millimeters wide, and the door lifting mechanism was also not activated. Now I complained and then someone from Kermi customer service came who installed the enclosure properly. That fits now. But now, the door that was initially installed crookedly has started squeaking horrifically when opening and closing. I believe the material has suffered due to the improper installation back then. I am now quite annoyed because this is an expensive high-quality shower and not cheap hardware store junk. Does anyone here on the forum have an idea what can be done or is the squeaking normal?

Well, the manufacturer's initial reaction was basically okay, even though the result is not quite right yet. Call and have them come again. It will work out, even if it is really annoying.

Whenever something squeaks WD40