Fraud at petrol pumps

Did you know what exactly you paid for petrol or are you aware from fraud at petrol pumps ?

Many of us not aware that the petrol kisok pump has a return pipe-line(in pink). When the petrol tank(in the car) reaches full level, there is a mechanism to trigger off the pump latch and at the same time a return-valve is opened(at the top of the pump station) to allow excess petrol to flow back into the sump. But the return petrol has already pass through the meter, meaning you are donating the petrol back to SHELL/CALTEX/MOBIL/PETRONAS .