Air Asia — No refund received

I booked flight in February 2020. Flight cancelled by Air Asia because of virus. Received two emails in July 2020 which promised refund No refund received. Talked to agent in August 2020 who promised refund by end of August.No refund received. Contacted Air Asia constantly about refund.
Cost of ticket: 2045.80 baht (50.58 pounds sterling)
Payment method: Nationwide credit card 17/02/20
Booking Number: B3J8KD
Case Number: 55118963
email: [protected]@yahoo.com
Name: Derek Roystone Thompson