Tneb — High Electricity bill

Sir im residing at medavakkam. My eb card number is [protected]. My regular bill is below 2000 and this time it comes around 12000 which is unacceptable. when I looked my bill history for last 3 bills, all are 300 units and Rs. 530. After i realised that they didn't come and take the reading by default they put approximate reading of 300 for last three times, and now they took real eb reading and all additional readings from old bills are accumulated and resulted in this large unacceptable bill amount. Due to their unresponsive atitude towards work my bill amount became intolerable. So kindly look in to this matter and resolve the high bill amount. Thank you