deactivate my caller tune Services

I want to deactivate my caller tune Services which has automatically installed in my mobile .I have requested the customer care officers of kolkata several times to deact my caller tune services but its of no use.the caller tune is still there. they are charging Rs30/- per month from my account .I want you should stop this service immediately . Other wise I have to take steps against it. My mobile No is -9836676445.Thats All.