I have been using airtel postpaid connection for couple of months. I deposited 5000 INR to activate the international roaming on my phone before I went abroad. After reaching USA I found that I am not able to make outgoing calls. I started using airtel call home calling cards with a toll free no. And when I returned to India I found that airtel charged me for using those cards.
1) How airtel can charge me when I my international roaming is not working.
2) Since I was using airtel calling cards only, how can they charge a customer twice for the same services?

Thanks,

Munish