Airtel — postpaid mobile bill-[protected]

Address:

Pune, Maharashtra, 411028

I am using airtel postpaid mobile bill. Since last few months my bill always incorrect and is up by rs 200 everymonth. Then i need to call them and get it corrected.
This months bill is again rs900+ ideally it should be around rs.460. When i spoke to customer care representative they said i have used some value added service was started on it and now i have to pay this value any how.

I am really not sure how come some service got started on my mobile and now they are forcing me to pay for it which i was not even aware of. Need help with this.

My number is [protected].