Airtel — International roaming charges within India

I was traveling in india in Arunachal and Airtel charged me extra Rs.499 for Bhutan network although I have deactivated my international roaming plan. It's not so much about the money as it's about this goonism way. They didn't ask for my permission to activate, they didn't inform they are putting me on Bhutan network, nothing was working or downloading but still charged me saying I used Bhutan network, I was some 50-60 kms away from Bhutan border and I didn't leave India border, more so with Covid restrictions, one cannot leave India just like that. Forcefully extorting money without any legit reason, permission or service provided. Very rude customer care executive, no sense of value of respect for long term customer, clearly they are ok to let go of a customer for Rs. 500. Cheapstakes.