Airtel — regarding to false internet bill

this complaint is regarding to the false airtel internet bill... m using airtel usb modem 4m past six months 4m now... it's a postpaid connection which is under plan of rs1000/month, unlimited free... but after initial month, bill is not stable... it increased to rs2800 in the month of march, rs1400 in may and now rs1600 in june...
i've so many times called and logde the complain regarding to this problem to the airtel customer care.. but there is no concerned i've received yet...
it is a request to the consumer court that plz help me out of this trauma as soon as psbl... there is only 1 hope left and so i m here...
details: mansi agarwal
c/o mrs. alpana vaid
e-480, g.k 2
new delhi-110048
airtel no: [protected] ( through which using internet)
my contact no: [protected].
thank you