Urban Company — ac was repaired, but stopped working within 90 days. fraudulent behaviour from uc

I got my ac repaired and gas refilling on 12 june2020. Within 90 days, i had to relocate. For uninstallation at old address and installation at new address, i booked urban company. Now during installation, ac mechanic said this there is no gas in the ac. I called customer care for repair under warranty, but they are saying i have changed address. If both the locations (Old and new) are serviceable by urban company, why they are not coming.
Also, they are doing tax frauds i guess. They did not give me any invoice. No gst nothing is there. These people are pakka chor. I am following up with consumer court to sue them for doing frauds. Exploring all legal options to take them to court and teach them a lesson at any cost.
They charged me ~7200 for 2 acs. And i am left with one damaged ac.