Value Prepaid water metering

Value Prepaid water metering is charging us more our tariff is more than other people on our complex us we can buy R150 and get 3kwh ,my neighbor on the same day can buy with R50 and gets 5.7kwh ,on R500 I get 21.6 KWh instead of 50.0 KWh I called the company they don’t take me seriously about my situation,I can’t afford water the basic thing ,my neighbors are 7 they spend only R200 a month,we are only 3 we spend R 1000 and there is nothing leaking in our house ,please help