same issue was also with me I have been charged for NU in jan bill..and only for 31st jan .I have contacted the AO of my area ,first time he was very rude and was not listening and ask me to bring print out of usage.Then after seeing it he agers and give Rs 870 refund for that bill.Now my feb unbill usage is around Rs 15,000. so I think after it is billed I have to revisit him...