Charged a service without mentioning it

Location/place: ahmedabad

Name of company/service: Vodafone

In the voucher given to me at the time of issue of the vodafone sim, they had given an option to activate miss call info I have to message ACT MCI to 144. But there was no fee mentioned in it. Once I activated I realised Rs30 is deducted from the account. Another message came from them asking me if you want to cancel the service then I have to send another message to them. I did the same and service was cancelled within 5 minutes. I had that service activated only for 2 minutes. But when I cancelled it the amount was not refunded. It was a case of misleading a leyman like me. My mobile number is 9727691947