Hvac Service - Vendor is not responding

HVAC Service advised me that we have to repair the leakage and refill the gas in Faulty AC. So they advise that we have to repair the AC gas leakage problem in their service centre. After multiple follow ups on that day at * pm at night they came for the reinstallation of AC. Then they told that now AC sensor is not working which was working fine previously. They tried to arrange the sensor but they didn't get the sensor then I had one spare AC I advised them you can use this sensor. They promised me that tomorrow we will arrange your sensor as this AC sensor is faulty but so far they didn’t come.
After * days again the same problem which they rectified began. Then we called them multiple time but after more than * week, no one from their team came to repair our AC they are continuously giving a false statement. I have recording of their false commitments. Mr Asif is the owner, he is a cheater. He is master of giving false commitments.
I think I have explained my problem so please advise which necessary steps I should take for this fake vendor so that no one can face the problem which I am facing now.
I am also attaching the invoice slip on which they have mentioned that I have paid them Rs **** and they mentioned * months warranty. But now he is not responding.
Please help.
Vendor/Owner Details
Mobile: **********
Owner: Mr Asif