detection of rupee with auto rendwal pack

Location/place: meerut

Name of company/service: airtel

Sir,
i have charged 36 rupee from last two month for auto renewal sms pack but i dont know that this type of service is activate on my number at this time otherwise i will stop this service at that time but without any type of confirmation the service has been activated on my number plz help me refund my money.My number us 9634829961