how to make free ISD,STD,Local calls from airtel for free

This is the latest hack done on the airtel mobile for making international free calls anywhere in the world and follow the following instructions
• dail 1802103
• then "welcome airtel" and will be asked”please enter your 20 digit number
• 1212121212#
• 1231231231#
• 1234567890#
• And you will be asked a question to insert number please put any of the above numbers abd you will be asked to put or dail any phone number you can make ISD,STD and locak from this service..