Airtel axis rupay credit card not working via airtel thanks app

I recently got my airtel axis rupay credit card. As per the terms it can fetch upto 25% cashback when paying wifi/mobile bill.

I have tried paying my wifi bill multiple times with this cc on the thanks app. But it's failing every time. My cc is working. I have made a transaction on big basket.

I called axis and they say that they see no logs of transaction and so issue must be with airtel.

I have called airtel multiple times with no help. They route my call to payment bank support and they say they can't do anything regarding cc payment mode. I have mailed 121 but they give generic reply to try other modes like upi.

The whole point of getting this cc was the 25% cashback. How do I escalate this? Please help.