Kenstar — Service center person is abusive and disrespectful

Address:

KENSTAR SERVICE CENTER, KARANODAI. MOBILE NUMBER 9566266593, 8825869556

I have had a Kenstar double cool DX air cooler for years, which I didn't use much. It is not working other than giving a mild humming sound which was repaired by Kenstar Technician after lodging the complaint at Customer Care.
Its motor was changed completely and serviced a month and a half ago and billed for Rs. 2800.00, but again facing the same problem.
Since I have the Kenstar Technician's mobile number who repaired last time, I informed them to address the issue. But, he didn't come telling me that he is assigned to some place around.
At last I lodged another complaint in Customer care and I was informed that I will be receiving a call in 48hrs.
But I received a call from a person from a mobile number [protected] after 4 days and asked about what the issue was. I explained that the Air cooler is not running. He cut the call all of a sudden without saying anything.
I called him again and again and at last he spoke to me giving me another mobile number [protected].
I called the given number and he said that the issue will be resolved shortly without giving me a specific date and hung up.
After 2 days, since nobody came to address my issue I called the same number again and he spoke to me very rudely saying that the issue will be addressed in some days. I asked him to give me a specific date. He said that the technician will come to my place in 4 days and cut the call.
He speaks as if he is the boss and speaks to customers like we are nothing.
Please Kenstar, change the service contract from these bullying persons to some good person.
Note: My house is situated with NH frontage and very close to the Railway station and Bus Stop. My building has Hdfc ATM and ICICI ATM and there is no problem in reaching my house.

Please help me and take appropriate action against these bullying men.