House owner treating us biasedly

As a family of 3 (myself, my husband, and a kid) rented a house in a 3rd floor terrace (2BHK). We were informed that water bill will be equally distributed among other tenants in the building. However, for our dismay this building has 2 water tanks, 1 small black tank to be shared by 2 houses ( 3rd floor, my house and 1st floor house(large 3bhk)), and a large tank for the rest of the 3 1 bhk houses. Due to these irrelevant proportion and planning, always we had a shortage of water and had to be requested for water. Only in mornings to avoid issues I started using some water from that large tank to balance. Now this month after the water bill, my house owner has charged us more percentage than others, when enquiry he simply says to vacate. He's not ready to make any arrangements for the betterment, instead simply stating if you cannot adjust just vacate. We had differences with neighbours for encroaching at the odd hours and disturbing us, because they want to use the terrace freely like before. Now since we are there, it's affected there entertainment. I've paid the van fee for a nearby school, it'll create an issue if I change soon. Please help me to deal with this.