GoAir — Ticket fare refund request against cancellation

Respected sir/madom.
My name is jeevan sudhakara panicker (Passport number-n8085351), i had booked one flight ticket (Pnr-ydfh9k) in goair airline on[protected] for august month - 2020 travel from muscat, oman to kannur, india. Due to covid pandemic situation goair airlines has been extended my travel schedule two times and unfortunately same pandemic situation is going still now. So, i contacted customer care (+91 [protected]) executive on[protected] for cancel the booking and requested for refund and they accepted. Airline team sent a refund slip on[protected] and said that amount will credit within 10 days. Still today i did not get my money to any of my account. I had contacted goair customer care several times and they are asking explanations questions about my reservation and always saying same story - within 10 days you will get money. Sir what can i do?
(Reference : on[protected] contacted mr. Abhishek sidram goair customer care executive.
Details submitted to him also with the above pnr, name, bank details etc.)
Kindly do needful action

Yours faithfully,
Jeevan sudhakara panicker
Mob: +[protected]
Muscat, sultanate of oman.
Email : [protected]@gmail.com