Airtel — Unauthorised international roaming charges

In bill dated 12th Sept 2022 daily international roaming charges of 649 /day were included from 17th Aug 2022 to 27th Aug 2022 on mob no [protected], totaling rs 4543 + taxes. (Total Bill – 6949)
I contacted local Airtel office at Patrika Marg and raised a complaint with service request no[protected], but I got no relief from this illegal international roaming charges on my bill. I do not understand how Airtel can automatically charge for international roaming beyond a one-time pack without renewal done by the subscriber. Is this another way to fleece the subscribers by this company.
Company is not responding to my complaint since 7th oct 2022
Dr. B. M. Singhal
[protected]