Air India — Refund status

My husband Capt Awanish Pratap Rao had his air india flight AI 9836 from Pathankot to Delhi on 2nd Sept 2021 at 15:25. The booking reference no is Z7K1J. The ticket ID is [protected]. His flight got delayed by 2 hours 15 mins. And revised timing was 5:40.
Since he had a connecting flight from Delhi to Mumbai on the very same day, he would have missed the flight because of this delay.

Hence he called Air india customer care and he was asked to cancel the ticket and refund will be issued regarding the same. But it's been more than 30 days and I haven't yet received the refund.

He called air india more than 10 times and they just put it on hold for long and won't tell the status of refund. We also sent an email for which they replied to fill the feeback form. The feedback form wasn't opening. We sent screenshot of the same to them but there is no reply from their side. We are not getting any response about the refund.