Airtel — airtel charging for international sms to [protected] number which we never did

For the past 3 months, Airtel postpaid plan has been charging me for some international SMS to the above number that i have never done. Just last month they have charged Rs 60 plus tax for the 12 SMS international which they are claiming that I did. This is totally unaceptable. When I called, they are not even waiving this charge.
Not only this to my other child number which is not even a smart phone, they have charged Rs. 150 plus tax Rs 30 X 15 for some Videopindw service which they say, I signed up for which I am not even aware of what that service is for, leave alone me opting for it. Airtel has started making so much fraud for compensating for JIO loss.