Airtel — my bill payment is too high

Hello my bill payment is too high i have a plan of 499 postpaid n my bill is charged more than 2600rs. I am looking forward to call me as soon as possible. I am not going to pay the bill until i dont get a call. They say i have used my internet, but they always stop my data after 3gb, so i was expecting same and its unfair! I want to have a word with someone from airtel and want to know the problem for high bill.