IOC- Petrol
Cheating, when fuelling

IOC petrol pump at BEL Circle, Gokula, bangalore, i've refilled my bike 2 times but when i say to person to fill 150/200 Rs petrol, they will start asking money and the charge appear on panel is 50 Rs. again he ask how much to fill? when i said 150/200 Rs. he again reset the panel and filled rest of Petrol,

But earlier 50 Rs filled petrol i not sensed when he filled...