[Resolved]  Idea Cellular Ltd. — Wrongly Billed

My name is Satyaprem Upadhyay and i reside in Gurgaon . I took idea postpaid connection for mobile (Mobile Number : [protected]) .
I was very regular in paying my bills for my phone.
Then I took a plan for using GPRS on my phone , in which unlimited surfing is free from night 11 PM to morning 6 AM , and i[censored]sed in between I would be charged with 1paise/KB .
I was using it and used to surf daily in the night . But one day after using in Night ( 16 Aug) when I dialled *147# to check my balance it showed sudden increase of 1500 Rs approx in my Unbilled amount .
I called customer care then and there , they told me that they did not have any information , and unbilled amount is different from the amount being billed so stay chilled .
I thought but still a sudden increase of my bill , I was really shocked.
Then after 2 days ( date 18 Aug ) the same process repeated and My unbilled amount increased by a sudden 300 Rs , I was again surprised , so I called customer care again , they told the same old story ,
But they told that we would have log after 2 days so call after 2 days , I called but they said they don’t know , and wait for Your bill to generate .
When My bill generated It was 3352 Rs ,a whooping 1800 Rs extra .And when i analysed those extra Rs where there in GPRS usage on those 2 days .
I called customer care and reported then problem in my Bill , I told that I do not understand that when my usage is free from 11 i the night to 7 in the morning , how I could be charged . They too did not understood the problem and arranged a call back from a higher executive .
When I received the call they said that your usage is free from 11 but u have logged in 4 min before 11, and our database notes the login time , so you are charged for the 3-4 hours after that with the rate of 1 Paise / KB , I told but when my usage is free from 11 why are u charging after 11 too .
Charge for those 4 min at the rate of 1 paise / KB n after that is free.
They again arranged a call from another executive , and told the same set of problems again , they said now the bill is generated , and we can do nothing .
I sent mails at customer care Delhi IDEA , then reported the problem , but again they were not ready to understand the problem .
They finally said that they we can waive off at max 100 Rs , but not more than that .I said but look in to the matter it is not just about 100 Rs . It is about almost 2000 Rs.
So please help me Sir as I am unable to understand as to how to proceed for this problem as Idea people are not ready to understand their fault. And This large amount for phone bill is unpayable.