Method:
1. First of All Go to Your Message Section and create new message. “STOP” & Send it to “1925”
2. Now for sending the given message your internet service with main balance will be deactivated.
3. Now get 3G loan 60mb by dialing USSD Code – “*567*10#”
4. Done!! Now wait for 24 hours.
5. After One Day or 24 Hours your Airtel sim will unblocked successfully.
6. I have tried it and it works many times for me.