Kent RO — The plastic Tank was damaged by the Kent person

Around a weak back, we had called Kent person from Nova Aqua System from Bangalore to replace the tap. The person who came was not skilled and he was not sure of what he was trying to do, and in the process he damaged the plastic tank and left the water leaking from the tank. After this incident we raised a complaint to the owners of Nova Aqua system and he refused to replace the tank and said that the tank was not damaged by his person. I request to replace the tank immediately and we are not suppose to pay for this as this is not our fault. Also i request you to keep trained people and not people who do not know there work.