Petronas — i'm complaining about the petronas sdn bhd at batu caves and more stations petronas at seremban.

21/9/2018, 3.45 pm AT STATION PETRONAS BATU CAVES.
this complaining its about the total volume of petrol in my car. i need to inform this issues to the petronas company in many times. but i failed to do that because i need to check many comparisons between other station petrol with petronas itself. therefore i was got the comparison between shell petrol station with petronas petrol stations. what i found which is when i filled the petrol at shell about RM20 ringgit malaysia my bar/sensor petrol in my car was increased about 4bars. BUT WHEN I FILLED THE PETROL AT PETRONAS STATIONS ABOUT RM20rggit malaysia, I WAS FOUND MY BAR/SENSOR PETROL IN MY CAR WAS INCREASED 3 BARS. SO i need to ask this question why this its happening and what actually the petronas trying to do?