Bharat Petroleum [BPCL] — Additional cash collection than bill amount during home delivery

Address:

Ernakulam, Kerala, 683572

I'm living in the Angamaly region in Ernakulam district, Kerala.our agency is Seena Gas agency. From a long time back, the delivery man is collecting around Rs.20/- more than the bill amount in which already included the delivery charges Rs.25.
Also the behavior of these people is very rude. They will not give the bill, unless asked him two times . no use in complaining at agency also.