EUREKA FORBES LIMITED - No service of my water purifier

I purchased an Aquaguard Reviva RO in **** from Kolkata and have been using it since then with regular AMC. I moved to Kochi in **** and got it reinstalled with yearly renewed AMC. Repeatedly over the last * years, I have been noticing black coloured insects in the collection drum of Aquaguard now and then. I informed the customer care. With great reluctance, they came and cleaned it. They told me the insects are entering through the side of the drum.
Last week also, I noticed black coloured object (looks like a cluster of dead ants) floating in the collection drum of Aquaguard. I informed the customer care and Kochi service centre. I requested them to come at once and clean it as I was unable to use the water for drinking purpose. It upsets me to say that so far no one has come to clean my Aquaguard in spite of my daily repeated calls to the service centre and customer care. This is when I am covered under AMC.
How can Eureka Forbes claim they are providing us with clean safe water when insects are floating in the collection drum of the "So-called purified water"?