Faulty prepaid water meter

At Cosmo city they installed these new prepaid water meters. My meter may be faulty as it runs faster then it should. Eleven thousand litres finished in 8 days, used by only 6 people. I called Jhb water & they said it's not faulty if there are no leaks. I then went to their offices at Turbine hall and a call was logged to Siyakhula. They said they don't know what's wrong with the meter as there are no leaks. They promised to bring their manager but it's been a week now. They installed these meters claiming they have been tested however its not normal for 30 000 ltrs of water to go in a month. I need this resolved by Jhb water however they not coming to the party. I have called, emailed, sent sms and gone there in person without any luck