I had subscribed for the Airtel data card service in the month of August 2008. The plan under which the subscription was made was Rs.599 per month for unlimited usage of internet. For the first two months I didn't receive any bill from airtel but since the amount was fixed I made the payment by my own. In the mean time I had also shifted my residence and soon my internet connection was disconnected. When I contacted Airtel I got to know that the monthly bill that was getting generated was Rs. 1800/- where as it should have been Rs.599. When I asked for the break up of this amount I was told that I am being charged for Blackberry and GPRS service which is over and above the 599 unlimited internet usage charge. I had never subscribed to Blackberry and GPRS on this number and it is also impossible to use these services through a data card which can be only used to surf the internet and nothing else. When I explained this to Airtel, after lot of argument they realised that the mistake was from their side and they assured me that the amount would be adjusted which they did. But again after one and half month I get a bill for Rs. 1800. They have not rectified the billing error from their side and are seeking the money. I have made it clear to them that till I get a proper bill I am not going to make the payment but they are insisting me to make the payment and visit the airtel centre to rectify this issue. I had already visited the airtel centre sometime back but still nothing has been rectified. Since the error is from their side they should rectify it and not make the customer run for this. I want to know if I can file a case if they continue to harass me for this?