Air India — Seat Selection Payment Refund

We've made booking for Pune Delhi and Delhi Newark, while booking the following PNR - JG6DD we had taken paid seats of rs 4500 and 350 =total 4850 rs..
We have upgraded the ticket to Business Class and so the we would like to raise a refund request for the seat selection payment.
Air pnr no - JG6DD
Ticket No.[protected]
RA no - [protected]
This refund request was raised by my travel company, it's been more than 120 days but Air India has not bothered to call back, reply to email sent nor processed the refund that we are eligible for.