Bharat Petroleum [BPCL] — Cheating in filling up petrol

At BPCL GT Road fuel station. People are cheated with filling petrol. The staff also bully people, on asking any amount of petrol to be fill, they first fill 50rs petrol and then fill rest of the petrol by misguiding people. this happen thrice with me. They fill 50rs petrol first and then became innocent as they listen for 50rs only. In all people end up in giving extra money as they fill rest amount of petrol by setting the machine and ask for the X+50rs by the consumer, Please my humble request to the officer please get it resolve as the lot of people are affected by the same and they are befooling people.