Kent RO — Fungus Formation On Kent Water Purifier

I ve changed two filters to my Kent water purifier just two months back. I noticed dirt particules in water and fungus I called to service center at Srinagar and they send service technician and he said need to change filters which we did with Rs 2800 cost after a month we found again dirt in tank and some formation of fungus but he left by saying it's coz of sun light, when there no direct sunlight and advised to clean tank weekly which we was doing already but after 15 days again same problem happened and again calling to service center and they left with same advice its coz of Sun light . They are technician zero don't know how to resolve the problem meanwhile my two children fall sick with intestinal infection. Who I blame Kent or there service team here in Srinagar J&k.