Idea Cellular — Unwanted subscription of caller tune

I have received a SMS reading “ Your monthly Idea callertune subscription has been renewed.You have been charged Rs.49 for month.To unsubscribe SMS STOP to 155223.

I had never subscribe for caller tune.

Immediately I had sent SMS to Stop to 155223 but I have been charged Rs. 49 for any such service .

You are requested to help me for refund of money charged, I had been charged by customer care during complaint but the customer also could not help out from this unwanted charge.Now I am not recharging my prepaid account due to un-satisfied service of the Idea Cellular service.
It is the great disadvantage if the cellular services for un-wanted charges applied by them.
Regards,