hi everyone, few days ago bsnl send me the broadband bill. its totally confusing. pls help me to understand its bill.here is the bill:LOCAL CALLS :-------------------------------------------------------------------------------CMR GROSS FREE DR CR UPTO7714 7 7 0 0 31/01/2009ACCS. RENT :-----------------FIXED FRM: 03/03/2009 TO: 31/01/2009BIMONTH RATE : 240.00CREDIT ADJ. :------------------NON OYT. TEL.APLN.DEPOSIT = 500.00(TOTAL BALANCE AT VREDIT = 0.00DEBIT ADJ. :------------------NPC-INST. CHARGES =500 =500.00ARDR INSTALLMENT = 333.33BROADBAND CHARGE : 200901Fixed Chrg tO : 310109 =290.32BROADBAND USAGE - 200901Grs :7316 Net : 1422 = 1137.22BROADBAND -MODEM PRICE+SALETAX = 1600.00OTHER TAXES = 7.36____________________________________________________FIXED MONTHLY CHARGES - 116.00METERED CALLS - 0.00TRUNK CALLS - 0.00DEBITS - 3868.23TAXES - 245.00CROSS AMT - 4229.00CREDITS - 500.00AMT PAYBLE ON BEFORE 27.02.2009 - 3729.00____________________________________________________________1. First of all i take the modem on rental basis. 2. plan home 500, free usage upto 2.5 gb. i use 2978090kb (chargeable units (kb) excluding night unlimited). they charged me 1137.22.in my calculation it should be (2909-2500) = 409x.80= 327.20____________________________________________________________So please help me what should i do.