Bangalore Water Supply & Sewerage Board [Bwssb] — regarding payment of sc borewell charge

Address: 560079

Sir this is soniya, we have our home in pattegarapalya bangalore with 1200sqft area with ground & first floor consists of two house respectively, my water bill rrno:w-122356.
So my complaint is that regarding my water bill sc borewell charges, we are getting charged 200 rupees, earlier it is only 100 rupees, it is continuing from last 6 month's, so i asked the respective person who issuing the water bill but he is telling u have more houses and also iam not billing your water bill, it's already getting computerized iam just issuing like that he told, but in our area, who are living with more than 2nd & 3rd floor they charged only 100 ruppee or less for sc borewell charges, i don't understand whats happening,
So please give me your clarification on this issue & also help me sir what next step i should take, & he changed my bill into domestic to multi house...
Iam ready to upload my building photo also if you want any further information... Reg,
Soniya