Johnson Controls: Hitachi Air Conditioning India Ltd: — fraud during ac installation of hitachi brand.

I have purchased 1.5ton split inverter ac of hitachi brand (Model no: rsog518hcea) from sargam electronics, malviyanagar, new delhi on 19th may 2020, which got installed at my home on 24th may. During the installation the technician who installed the ac, charged me more in comparison to actual cost of the components and also didn't provide the bills for that. I came to know about the actual cost when my friend who purchased the similar product with me on same day from same shop, shared his installation bill with me. The details are as follow:
). For 3 m extra copper tube he charged 900*3=2700 instead of 750*3=2250.

2). Also he charged for full 6m length 4core wire (Need to charge for extra 3 m only bcz 3m is given by company itself, similar to copper tube).

3). For wall stand i have paid 850, for which he also didn't provide the bill..

I have paid rs 4270 instead of rs 3460


I have tried to talk to concerned technician and hitachi service centre multiple times since last 5 days but with no satisfactory response. Now they have stopped receiving my phone calls. I have also dropped e - mail multiple times to hitachi customer care but with no response. The extra money paid is few in comparison to actual cost if ac but when no one is listening to the complaints i am feeling like cheated.
I need bills along with the compensation to extra money paid. I kindly request you to look into the matter and take necessary actions.
I am submitting my purchase bill and screenshot of the money paid to technician (Which i have paid via phone pe).