Viessmann Air Conditioner Not Working – Poor Installation and No Service

I purchased Viessmann wall split air conditioning units for my property in the Dalyan region of Ortaca, within the municipality of Muğla. From the beginning there were serious problems. Around 6–7 months ago, during the initial installation of these units, the workmanship was very poor and my walls were damaged due to careless and shabby work. Now the situation has become worse because one of the air conditioning units has completely stopped working. Four days ago I contacted the service team and they asked me to send a video and additional information, which I provided immediately. After that, they stopped responding: they have not replied to my messages and they are not answering my phone calls. This lack of communication and after‑sales support is unacceptable for a system of this scale and cost. I have an invoice/contract and video evidence of the problem, and I expect Viessmann to honor the warranty and repair the non‑working air conditioner as quickly as possible. I request that the company urgently send a competent service team to fix the unit properly and to take responsibility for the previous poor installation and the damage caused to my walls.