Indian Oil Corporation - Cheating at Indian Oil Petrol pump

Every day the staff at Sri Srinivasa Manikanta Petrol Bunk (Indian Oil) opposite Govt Polytechnic College (Bypass to Seven Road Junction road) are looting customers by filling the fuel for lesser amount than they pay. Whenever a customer requests for fuel of Rs.*** or Rs.*** or any higher amount, they fill for at least Rs.*** less than what you have asked and paid. This happened to me * times earler in this petrol bunk itself. So today i decided to catch them red-handed. I have swiped my card for Rs.***, the guy standing first in the picture tried to divert my attention by speaking something, then he filled the vehicle behind me for Rs.***, then came to me and filled my vehicle for Rs.***. I acted as if i didn't notice anything, but before leaving i asked for the computer generated bill. He had no choice but to admit his mistake.