If you have the relevant proofs and BSNL is not fixing the invoice for you, you should probably file a lawsuit in consumer court.
Yeah you are right.. Thanks all for the help... And pardon my tone if it's found rude (which I didn't intend)... Thanks againFirst thing is that when you ask for a solution / help be more courteous and less arrogant which can be seen from your posts .. Listen to the advice people give you here they are experienced .. I know i gave you no solution but I was very tempted to just reply reading the tone of your posts .. Hope you are able to get help and have your issues corrected ..