It is a offer by docomo dial 543211985 and select song its free of cost and you get 5 day free hello tune
last day deactivate it by sms
type STOP and send To 543211 (toll free)
After Reciving deactivation sms again call 543211985 and select song for free and repeate this process for free hello tune.(AIRTELTRICKZ.MOBIE.IN)