BSNL broadband Home UL 750 plus — Excessive DEBIT in Bill

Sir, I just recieved my bsnl bill for the past FOUR months... and everthing in my bill is normal apart from the "DEBIT" .
My DEBIT has been conted to be ->151, 570.27
TAXES : 15, 061.84
GROSS AMT. : 166, 632.00

However i have 750 UL plus. I can say that certainly since my Phone Rental is 0.0 . and it has been given that "fixed charge" for broadband usage is :750.
I have a Sulabh plan so my metered calls is 0.