Pathetic Service

i recently put in a claim for a water leak in my house. Nedbank Insurance sent out two plumbing guys. The one went to the back of the yard and one in bathroom. The guy in the bathroom said the tap is finished but never detected where the leak is really coming from. Ths is pathetic service. How can i loose 400 Litres of water in 3 hours. All they said was the leak is in the tap. These guys have no idea what they speaking about.Please get people who know what they doing because too loose 400 litres of water in that amount of time where is the real problem? i have never claimed from the insurance since i have been with Nedbank. Now they declining me because these plumbers incorrectly detected the problem and clearly the leak is not where they saying. I have no choice but to move to the Ombudsman should this not be rectified.