Harassment by builder

Hello Sir/ Madam I am facing water crisis in my flat since last one year as i raised voice against builders poor quality construction and wrong practices in District consumer forum. Actual problem started from the day we sent legal notice to builder for damage repair orruring because of his poor quality construction. Since then builder use to cut our water supply when ever he feels like harassing us. As we reside on 3rd floor of G+4 building When we approached 2nd floor below our flat they said they are not facing any problem and getting normal water supply.This incident of cutting water supply is not first time. previously when we use to make police complaints they refuse taking our complaint and ask us to approach water board for water issue and at the very next day of approaching police we use to get normal water supply as other flats get. Hence, this time we did not make any complaint regarding water supply because first time when we made complaint to police even though he didnt took our complaint in written but, when visited our flat on next day he found normal water supply and we were proved false in front of him. we were answer less. Very confused whether what to do, if we go to police again we will be proved false. Very terrible situation, Please advice what can we do?