Tamil Nadu Electricity Board [TNEB] — even bill calculation for lockdown period is wrong and they are charging high amount too.

My consumer number[protected]. Iam residing in udumalpet. I had paid an amount of rs.680 in april month as mentioned by eb dept through sms. Now when the reading checker came he had calculated reading for 4months together and imposed bill with heavy surcharge.. After that he minused that april paid amount from the grand total. This is cheating. He is supposed to minus the units first then calculate for rest of the reading. He cannot come for checking is not my fault, if given any option online for payment according to our usage also saved us from paying so much surcharge. Kindly take this matter and do tge needfull