Tata Power Orissa - Unfair billing one bill for two month

I am a consumer of TPWODL and getting my electricity bill once in a couple of month since last few month after TATA POWER acquired WESCO and they are billing once in a two month resulting increasing electricity Unit for multiple slab rate. Example; As per TATA power bills for * month,
Total unit ***
Bill slab:
i. ***xRs.* = ***
ii. ***xRs.*.* = ****
iii. ***xRs.*.* = ***
TOTAL BILL AMOUNT: **** for * month

ACTUAL

Lets assume electricity consume for a single month, ***/* = *** unit/month
Bill slab:
i. ***xRs.* = ***
ii. ***xRs.*.* = ***
TOTAL BILL AMOUNT : ****/ONE MONTH
*month bill should be ****x* = ****


Difference is Rs. (****-****) = Rs.***

So, TATA Power is charging Rs.*** extra for *month from each consumer.


Please Help..!