Airtel — cheating by airtel vas service activated on airtel number without my consent

Address:

Thane, Maharashtra, 421301

Last week 4th april 2018 vas service "ask my doctor" was activated without my prior consent. Called customer care service regarding the same but no use.
They refused to repay me saying that "you have activated it via internet".
I have told that no gprs/internet is activated on this no "airtel [protected]".
How can any airtel service provider activate the service without proper consent o[censored]ser?
Rs30 of activation + rs15 of renewal they have charged on this number.
This matter is really very much critical and looks like fraud as many more people may have faced the same thing of vas getting activated.