Apartment Issue

Sir good morning this is Vijaya from Chennai. We are living in an apartment. Here there are 8 flats. We are residing on the ground floor. We are having only one common overhead tank. Ten years completed.Last year all over Chennai there was a severe water problem. During that time one of the owners residing on the second floor was taking care of the maintenance work. We didn't get sufficient water. We are having 3 bores.All the there is not sufficient water. So we decided to get lorry water. Here before we didn't get any water problem. They collected nearly 4500 for the motor and other pipe connections work. But that time they didn't openly say that they are going to put two bags of cement inside the water tank and they inserted some pipes inside the water tank they told they are leveling. But we are not aware of all those things. After that, we didn't get sufficient water.Then only we came to know that the water coming to the ground floor is diverted to the second floor. Now we are facing a severe water problem. Because purposefully the tank was emptied by the persons living on the second floor. They are causing unnecessary trouble for us by parking the vehicle wherever they wanted.Frequently the motor is getting repaired. When we took the maintenance the person continuously troubling us by repairing the motors, keeping the automatic sensor ball to touch the water. When it is touched the automatic motor will not work. whenever we calling the mechanic that time they are keeping it in the original position.I have a doubt that whatever we are speaking they are overhearing us. And all the other owners are also believing the person only. He was acting very smartly before them. Recently he changed his bathroom closets. From that day only the tank was getting empty frequently. The entire third floor where the tank is situated is common only.There he was planting a lot of plants without anybody's permission and spoiling the floor. Every day morning whenever we are getting we are not getting water. It is troubling us both mentally and physically. Because we are only operating the motor. For nearly fifteen days we are suffering continuously.We want to remove the internal pipes inserted in between. Kindly help us in this matter. We want your guidance and consultation in this matter. Thank you.