Mitsubishi Electric - Regarding the problem in AC

On **/*/**** I purchased Mitsubishi AC from Ahad cooling solutions, Vijayawada consists of one year warranty which is recently got the problem and unable to on the AC. Then I contacted Ahad solutions for servicing then he sent one technical person to solve the problem. He checked and concluded that the motherboard problem then he took to the service centre and came back after one day. He replaced the motherboard and tried to solve the problem but he failed to resolve the problem. Again he took the motherboard for servicing and after two days another technical person came to resolve the problem but he also failed to solve the problem. Then he told that this is a complete motherboard problem we will replace it with a new one and he left. Since two days I am trying to call both technician and dealer they were not responding to my calls. Kindly do a favour in this regard.