Steps By step -:
1) Dial *567*10# And Request 50MB 2G data Loan.
2) After Getting 50mb loan, Comose New Sms To 121.
3) Type NIGHT and send it to 121.
4) Now remove your sim from mobile,
Insert your sim on Night 12'o Clock.
5) Start Browsing And Downloading With Default setting,
6) After complete 50mb, switch off mobile or remove sim (your wish)
7) Now insert your sim on after 6am.
8) Now Finish the cashback data and open one.airtel.in/ifb/iportal/index.html normally.
Now you are unblocked..