Avoid getting cheated in petrol bunk

Few days back had to fill petrol in the petrol bunk, It happened that a guy came to get the money, and just that second the meter which was running at 405 jumped to 500 rs. I found and asked about it, then he said there is some voltage problem, and filled the 95 rs then. I guess people need to be careful till the complete fuel is filled for the amount. Always there are people who come and try to cheat you, especially when you are at the petrol bunk in bangalore.