Shocking customer service- more expected from a German company!!

Bought a metallic ( stainless steel) fridge some years ago and it's been working very well. Last year I noticed some small rust marks appearing on the bottom edge of the door. I contacted Bosch and was told by their technician, without him having seen the fridge that our silicone broom had damaged the protective layer and that we would need to pay for new door if we wanted one. I asked to speak to a senior manager several times but was ignored. THIS IS THE WORST CUSTOMER SERVICE I HAVE EVER EXPERIENCED FROM A GERMAN COMPANY!!! BOSCH GERMANY SHOULD BE ASHAMED!