Builders brand geyser manufactured by Ariston

What a horrible customer experience. I have bought a geyser(Builders brand manufactured by Ariston) at builders superstore commercia in June 2023. On the first week of October it started to not heat up the water. i thought it is the element and thermostat but it was not. Reported the issue but they (builders and Ariston) two weeks to respond. They do not want to change the geyser. now my money is down the drain.