Airtel — imusic vas fraud

Address: Chennai, Tamil Nadu, 600037

Airtel Dth has been charging me 51 rupees extra for the past one year without my knowledge.
My service ID is [protected]-001
I have been using TN HD basepack which costs Rs.270 per month (Nfc and subscription combined)
But they have been charging me Rs.321 per month
I called the customer care once and asked why the value doesnt tally but he never mentioned me about the value added services.He only mentioned when the validity will get over but never mentioned about the value added services.
Only today I came to know that they have been charging me Rs 51 extra for an added service called imusic which I have never asked for and know nothing about.