Siemens HI133FEW0T Oven Not Cooking Properly Since Purchase

I bought a Siemens HI133FEW0T built-in oven from your Izmir Konak Alsancak Talatpaşa store, and since the first day I have not been able to get a proper cooking performance. Nothing I bake rises properly, the edges of cakes and pastries dry out while the inside stays raw, and the same problem occurs when I cook meat products: the outside browns, but the inside remains raw. Because of this, I have not been able to use the oven efficiently for about four years. During this period I opened two service requests, but nobody called me back or returned to me, and in my most recent service request I am still waiting for a response. I have also seen many similar complaints about this same model, especially regarding units from the 2022 production series, which makes me even more concerned about a possible chronic problem with this product. As far as I remember, we extended the warranty for 5 years, although the invoice is in my husband’s name and I do not have the invoice details at hand right now. Considering that I have been experiencing these problems from the beginning and have not received an effective service response despite my applications, I request that a detailed technical inspection be carried out as soon as possible and that, if the defect is confirmed, my oven be replaced with a properly functioning one or that a refund be provided.