Kent Ro water purifier...worst nightmare ever expe. Review on Kent RO System

I have purchased Kent Ro water purifier 3 months back... immediately after installation the indicator was showing mineral content was low.i called the service.the service man manipulated something inside the machine and indicator turned to show good mineral content. problem again started off and on and the inefficient service engineer s come and manipulate to show it good but couldn't tell me the reason behind.They stopped coming after 4 th complaint through app and were closing the complaint without attending the machine.i demanded replacement to the company but they are denying stating that replacement is not included in their policy. I am surprised that neither the engineers could correct the problem nor r they replacing the machine then what is the meaning of warranty? I am feeling helpless because water quality is very poor in my locality and I had purchased it for the safety of my kids with my hard earned money.it is a shame for our country that consumers are being cheated by this type of water purifier company like Kent that carries a big brand of reputation and warranty means nothing and service quality is the poorest