Use of alternate parts on cars still under warranty without notifying the client

King Price Insurance is showing me flames and refusing to take responsibility. I submitted a windscreen claim for my Mercedes-Benz A200 AMG line sedan in March 2025 and it was approved, thereafter I paid the excess and DGC called to schedule an appointment for replacement nowhere during this time did kingprice notify me that they will be replacing my original mercedes-benz windscreen with an alternate, so after replacement I noticed that it was an alternate and not original so I called to find out why this was done as it would affect my warranty I was asked to request and send through a letter from mercedes-benz stating that my car was still under warranty and that only original parts can be used of which I did, thereafter they changed tune and said they don’t care that it will affect my warranty they have every right to use an alternate. Meaning they omitted this material information from the onset intentionally. As it stands the windscreen they installed serves no purpose to me or my car what am I suppose to do with it? How is this even ethical or professional?