IFB Industries — Warranty issue

I had purchased ifb washing machine 3 years ago. The washing machine has 4 years super warranty and 10 years spares support. Every year ifb is providing maintenance service to the machine. But every year they are billing me rs.1800 to rs.2200 for water softener unit and drum cleaning power.
Whereas washing machine was supplied to me with water softener and as such water softener is part and parcel of machine and same falls under warranty of the machine like every other parts of the machine and cleaning, lubricating, repair and replacement all of which falls under warranty. Further i checked goggles web site and come to know that water softener life span is 5 to 10 years.
I put it ifb is willfully replacing water softener and collecting double the market price for water softener and drum cleaning powder. There are several types water softener available in market wherein the water softener unit can be opened cleaned and reuse it for several years without replacing.
Therefore