Charging my postpaid bill in excess amount by showing false internet browsing

Location/place: Greater Noida

Name of company/service: Vodafone

I am using vodafone postpaid number 9560823804 and this month i subscribed to 2g internet pack of Rs 125 of 1 GB data but the internet speed in vodafone in 2g is so much down that after using this pack for 8 days from 25 June to 02 July,on 3rd July i called customer care to stop this internet pack and finally the internet pack is deactivated on 3rd July at 7 PM in evening..but what i saw in bill is that my browsing data as produced by vodafone is 1.23 GB and in 9 days i consumed only 34 MB then how is it possible that i consumed 1.23 GB on 3rd July and now vodafone is charging me Rs 795 for this fraud.if anybody can help me plz help me..