Panasonic - AC Stopped working in a month

We purchased a Panasonic Inverter AC from Sargam Electronics, Gurgaon based on the sales person recommendation and trust on the Panasonic brand.
Panasonic assigned an engineer named Sanjeev but some other people came for installation who were completely unprofessional and untrained. They were unable to install for full day and kept drilling holes. Next day ac was installed somehow but within a day it started leaking water, showing the incompetence. Finally when complained they sent Sanjeev who came in Panasonic uniform and said installation was done wrongly and corrected the pipes etc. Ashok was supervisor over the call. This was in mid April.

Today even before completion of * months AC stopped working,they are telling us Gas has leaked and they will refill and identify leaking points. We have to call ** times to get the mechanic and also it's not sure that gas will not leak again. It has given us nightmares even after spending **,*** on a branded AC we have to live without it for days. We want them to take back this defective appliance and refund our money. Panasonic team doesn't own responsibility for untrained people or faulty devices and giving us a tough time.