false claim made by company for product as special feature

Location/place: faizabad

Name of company/service: kent water purifier

i ‘ve taken kent grand plus in 2010 from jalandhar punjab.filter change alarm was the one of the main selling proposition for the product n even mentioned on the produst.again it’s mentioned that filter shd be changed after one yr or after filter change alarm. after one yr when i inquired abt the filter change alarm they said after cheking my system that ur filter is perfectly fine n there is no need to change as u r using only 8 litres of water daily whereas the capacity of filtering is 70 litres per day so u need to change ur filter after 3 yrs.but recently when i’ve called person for servicing he said ur filter is in bad shape n giving tds 228…like tap water but there was no alarm from system.after telling this thing to their service manager they ‘re telling me that u ‘re telling lies abt the filter change alarm.so tell me what shd i do in this case abt false selling proposition of company…..where shd i register abt the company n get justice