Siemens Refused to Replace My Oven Despite Visible Defects Not Caused by Me

I bought a Siemens built-in set (hood, oven, and stove). When I started using the oven, I noticed a dent on the bottom, like an inward bump. When I had some free time, I called for service. Since the hood was also turning on by itself, I showed the technician both the oven and the hood. He dismissed the issue by saying it was a user error and left. However, it’s impossible for something to fall into the oven and cause such damage to the metal. I only use the oven's trays and nothing else. Over time, the dents inside the oven started to increase, so I called the service again. After inspecting it, they said, "If you had reported this before using the oven when you first bought it, we could have replaced it, but now we can’t do anything. You can file a complaint if necessary." As you can see from the pictures, this deformation can't be caused by user error. I am requesting that my grievance be resolved. I hope the company, which we paid extra for thinking it would offer quality, will stand behind its product. Otherwise, there will be no point in paying more for a well-known brand.