Airtel
Trying to deduce money from account wantedly

I subscribed for Airtel "music on demand". The next month a message came saying that the would reduce Rs.30 from my account for the monthly subsciption. They also sent a no. for deactivating the service. But when I dialled the no., they asked to recharge for Rs.30, 20&10 and never said about deactivating the service.