Bosch KGN86HI30N Freezer Door Does Not Seal - Service Failed to Fix the Issue

My Bosch KGN86HI30N/02 refrigerator's freezer section keeps triggering a temperature alarm. When I purchased it, it was Bosch's top-tier model (Series 6) available in Turkiye. My expectation from any home appliance is that it should work trouble-free for at least 10 years, and if an issue arises, it should be resolved promptly by an authorized service. The freezer door no longer seals properly—it’s like a door without a latch, failing to close tightly. I recently learned that, even in Bosch’s high-end refrigerators, the fridge and freezer compartments are interconnected. When the fridge door is closed, it creates reverse pressure in the freezer, which causes the already problematic freezer door to open slightly, triggering the temperature alarm. We requested a service visit, but the technician who arrived was inexperienced and unprofessional. He looked around aimlessly and concluded there was no fault with the refrigerator, charged ₺700 for the service, and left. Amusingly, he even advised us to unplug the No-Frost refrigerator for 48 hours to let it defrost, claiming that this would resolve the issue. We insisted that the problem was with the door not sealing properly, but he dismissed it, saying, "That's normal for freezer doors." I also have a Bosch deep freezer, and I need significant force to open its door. How could this be normal? We unplugged the refrigerator for 48 hours, stayed without it for two days, and moved our food to our neighbors’ refrigerators. The result? Absolutely nothing changed. The door is still loose, still opens slightly, and the temperature alarm is still triggered. I called Bosch’s customer service, explained the situation, and stated that they had charged us without providing proper service. I requested a refund and also asked for a truly competent technician to resolve the issue. Today, the company called back and said, "We cannot refund the fee because your warranty has expired." Unbelievable! This is the state of a giant company like Bosch—what a shame! I used to be a very loyal Bosch customer. Any issues I had in the past were handled promptly, which built my trust in the brand. I believed they prioritized customer satisfaction. Now, I realize I overestimated the brand and ended up paying more for a level of service that doesn't exist.