Unsubscribe Airtel WAP(subscription, TextBasedServices)

hi,
I've received a Sms from Airtel "Thanks for using (subscription, TextBasedServices) subscription service on Airtel WAP. You've been charged Rs.20.Enjoy http://gclub.in

please give me a correct solution i had loss lot money due to this wap even am not using this...
please unsubscribe this in my mobile ...
MY MOBILE IS 9003546006
PLS DO THIS AS SOON AS POSSIBLE...