Jiomart — No support on product installation from customer care

I have order water purifier on jiomart last month and it was delivered in last month itself, i also paid for installation at the time of order placement and so dar there is zero support, they are disconnecting calls, closing mail tickets raised, no reply on chat and not able to log complaint on website, there is no option to return the order as well. Around ~16k of my hard earned money is at play here. I don’t know where else to go so raising complaint here.