Flipkart - Flipkart Service and Technician Rude Behaviour

I have purchased LG AC from Flipkart, and I received the product. I have booked the authorised installation with extra amount. Flipkart send an installation technician to my home. Technician said, the company provided inlet and outlet pipes will not suitable, I will provide you the original inlet and outlet pipes with extra **** rupees. And also he has taken the company provided pipes with him. I thought, he is authorised person, he will provide original pipes. But, he has purchased some local pipes and installed with those pipes. I asked him to install it one place, but he installed it in other place, wherever he wants. Mine is very new house, recently we constructed it. He has unnecessary damaged walls. I didn't asked him for this point. While leaving they were secretly taken the extra accessories while my mom went to other room, my mom came back and asked them for the accessories, they are getting angry on my mom. They were thrown those accessories on us and demanding for extra amount. We told them, we already paid extra amount than the actual amount. The technician was warned my mom, "I will see, without me, how could you maintain your AC". After that, I called flipkart customer care to complaint on this issue. Flipkart executive asked me for the GST bills. Again I called the technician, and asked for the bills. He scoled me on that call and he cuts the call. I have been giving complaint on this issue to flipkart from April **th. But, flipkart executives are saying wait for **hrs or **hrs, backend team will get back to you, but the backend team is not looking at the issue. They are closing my complaint without any inquiry. Multiple times I complained they are closing it. Literally they are taking complaints and closing by themselves. And also my AC is not working properly. I am giving complaint on this issue as well. Flipkart is not responding properly.