Aquafresh — Aquafresh water purifier , company denying to send any men to fix it

I ordered aqua fresh water purifier from zepto, and was not given any bill, and now just after 7 days the purifier stops working, the guy is not receiving our phone, and one time that he did, he asked us to send the bill number, which we don't have, and we are in bad state, as we don't have any other way of drinking water