Teka Customer Service Not Providing Help, No Way to Get Appointment

On September 13th, I contacted Teka customer service to get the authorized service number for Mugla-Mentese. I called the authorized service and reported that one burner on the hob was not working. I sent a photo of the label with the serial number. They said they would schedule a service and closed the call. I waited for two months, and in November, I created a service record through customer service, and they assured me I would be contacted. However, I never received a call. In November, I called again, was promised a callback, but unfortunately, I was not contacted. This place is small, and there are no alternatives; local appliance repairmen say they need parts, and they insist on an authorized service – a brand operating worldwide can't get a repair done by its authorized partner in a small town. What would you do if you were in my shoes? And when the service finally arrives, what would you do next?