Airtel — internet settings and GPRS settings

Address:

South West Delhi, Delhi

i recently bought nokia c3-00. and have this internet pack from airtel, but when i was using it was deducting charges for per kb, then i asked airtel custom care for mobile office. after that i started using net from the icon made on home screen for web and it will not cost me
but whenever i use opera mini or use any application and game which need internet connection, then it starts costing me... they stated deducting it from my balance.
and whenever i download any application or game it gets downloaded but a golden key on the icon of application and then it never runs.
and please tell me how to get gprs settings in nokia c3