Kenstar — horrible customer service issue not resolved even after 4 months i need replacement or refund

Website:

www.kenstar.in/home-appliances

bought a kenstar 25l storage geyser kgs25w5m in october 2017 and had it installed by kenstar.
later in january 2018, it had a problem and it was not working and we called kenstar customer service and they sent their representative.
he inspected and told us that tank got damaged and needs to be replaced and also said that he would order the tank and it will take 2 weeks maximum to get the tank and have the repair done and we need not pay any money since it is in warranty
from then (January 2018), problem is not resolved. Every time when we go and ask they are saying they didnt receive the part yet and it would take one more week. We tried contacting kenstar customer service through phone and email as well.. No one gave proper response
if they cant provide a spare part or service even after 4 months, wont they replace the product?? Doesnt they have a timeline in which they have to repair the product in warranty or they can take as long as they want??? How long do the customer has to wait?
kenstar didnt respond properly at all (Email phone or watever). I said i will file a consumer case and they dont care at all
i request for refund/replacement immidiately.

Request id: viz[protected]
Raised on:13th jan 2018
Promised date to get the repair done: 2 weeks max (27th jan 2018)
Till date, issue not resolved. Daily i have to call them or email them or reach out to local office and they wont respond properly