[Resolved]  Airtel Hello Tunes — airtel hello tunes

i had subscribed to airtel hello tune from the movie ghagini, kaise mujhe tum milgayee since last 15 days and suddenly all of sudden without any confirmation nor prior intimation my hello tune was changed to airtel hello tune.i received an sms from airtel on 6780 stating that my hello tune has been changed free of cost.but i had not made a request to change my hello tune. but even then my hello tune was changed.
when i pointed out the error was from airtel and rectify it . the airtel executive changed and restored it to my original ghajini tune but in the process charged me Rs.15 for the song.
when i brought it to airtel's notice they said that since i have changed my hello tune i will be charged again for the change in hello tune.