[Resolved]  BSNL Broadband — Wrong Calculation of chargeable data in bill

I have BSNL broadband's Home500 in which i have data transfer limit of 2.5 GB during daytime(8 am to 2 am) and unlimited data transfer during 2 am to 8 am. I use task scheduler utility of windows system which starts my torrent client software which i use for downloading from p2p network, at 2:05 am and automatically closes same application at 7:55 am. Hence i make connection well before 2 am leave my pc on for downloading.
I got my connection in January of this year and i had been doing same from then. I used to get my bills with correctly calculated data transfer i.e. data transferred during daytime and data transferred during 2 am to 8 am clearly differentiated. But from month of May i started to notice that BSNL is not differentiating data transferred before and after 2 am. The data transferred till 2:20 or even 2:30 was also being calculated as chargeable data. Same thing continued in June, July and till date. I July because of this wrong calculation i got my 2.5 GB data limit crossed and it showed excess data of nearly 500 MB costing me unnecessary nearly 400 Rs. more than regular monthly bill of 570 Rs. I have filed a written complaint to BSNL authority of my area but in vain. First of all the person in that office was not even aware of the technicality of the issue regarding my complaint. She said that she need it to be discussed with higher authority and then only she can accept my complaint. After some days she calls me and says my complaint is not valid because what start time of the connection is important, that means if i connect to service at 1:59 am and continues using service till 8 am the all data transferred meantime will be considered as a chargeable data. I was shocked to hear this statement of her. I mean this doesn't make any sense, instead it pretty lame excuse to hide BSNL's miscalculation in billing and to loot costomers.
I think if BSNL is providing plans which gives users unlimited download during certain time period then it is BSNL's responsibility to differentiate between data transferred during that period and rest of the day. My second point is that the log which shows start time and stop time of connection is made by BSNL's billing system. That means even if do not disconnect my connection say from 1 am to 8 am, still it will show in the log more than one sessions of connections. You can clearly see this in your bills also. All i am asking is that why can't BSNL make their billing system more accurate so that it can make log of data transferred till 2 am and different log data transferred after that; even if connection is not altered from user's side?
I have already paid the excess bill and still waiting for my complaint to be addressed by BSNL. The local authority is as co-operative as needed and just delaying the issue. The person has refused the reliability of the printout of the detailed billed from BSNL's own website and has retrieved the detailed bill from her "reliable source" but failed to email me after may attempts and not even able to give it me through USB drive or CD because computer at her office are unsurprisingly outdated which don't even have USB ports let alone CD drive. Here I request u all to suggest me if there is another effective way to get my complaint resolved and rebate from the excess bill which i have paid.