Cheating - the qunatity of fuel filled at petrol pumps

This must be reported at various places. The problems I see as the attendants at the petrol pump cheat the customers in various ways.

A.

1. Engaging customer in conversation and filling less fuel.
2. Not resetting the counter to zero.

B.

1. Filling less fuel than that actually was asked for.
2. Then continuing from the point of earlier reading till only the balance reading, so as to make it appear as it was started again from zero.

There can be many more stories. Please help me find all types of such cheating.