Indian Oil Corporation [IOC] — cheating staff

1week ago i refilled from here for rs. 300 and runs 137km after 3 days i refilled from other bunk (Shell) and refilled for 300 and runs 210km. Then i got some doubt but i blamed bangalore traffic. Yesterday i refilled for rs. 200 and ran just 63km. If you are using card, they'll distract you like those who fill the fuel wont give you the swiping machine. Instead another guy will come and stand opposite to the machine. They won't take normal time to refill. Last day i noticed something called preset in the meter.