Air India — Cancellation and refund

I had contacted Air India customer care number on 4 May 21 for cancellation of two tickets.
1) PNR 'YXZWG' containing ticket nos[protected],[protected],[protected] and[protected].
2) PNR 'J521N' containing ticket nos[protected],[protected],[protected] and[protected].
Since, then I have called on the customer care number many times. I have also sent many emails & reminders to Air India for information regarding cancellation charges and refund. No body gives a reply. It has been more than a month and no refund has been received. Every Air India representative provides a new Email ID to contact. I send a mail and of course no reply/solution is received.