Airtel - Billing fraud regarding international roaming

It's a case of fraud. I deactivated the international roaming. Airtel again activated the same on my number. When you receive incoming calls while travelling abroad, you don't get any information from which SIM you are getting calls from (Local Airtel or International UK SIM?). I raised this issue multiple times with Airtel. It happened twice - Airtel activated the roaming * times and the first time they agreed on it saying it was done by mistake due to a technical issue and they waive-off the international charges. But they did it again, and this time they are asking money.
Now I will not pay any amount against international incoming calls. If Airtel doesn't resolve this issue, I would take below actions:
*. I would raise this concern on social media channels to expose this fraud
*. Would seek legal action against Airtel.
To ensure I get justice in that matter.