Eureka Forbes — Bought AMC from them and not changing Candles as committed

We took Eureka forbes water purifier nearly 10 years back. We pay AMC of rs. 8000 every 2 years. They will change all filters twice and will replace any part if damaged within this 2 years. They changed the filter candles while paying the amc on aug 2018. For changing the 2nd., time as per amc. rules, they are saying that they have already changed our filters 5 months back, which they didn't do at all. We wrote to customer care, call customer care every 2 days. The reply will be we are talking to the business partner regarding this issue. The dealer of our district ie, guntur say you can raise this complaint to who ever you want, I won't change . We trusted the brand name eureka and paid to the dealer whom they appointed. Now can you help me in getting justice. We wrote to customer care of Eureka Forbes to check the bar code of our filter candles inside our water purifier to know when they have been replaced. The dealer has to show the proof of replacement, even that they are not doing. We have been totally cheated by genuine company like eureka forbes.