Virgin Amex Free flight cancellation

[burmans]

I've just had to cancel a free flight (Virgin Amex) due to coronavirus restriction, as I understand this will be credited back to my account but unsure what the expiry date will be. Anyone with recent experience of this?

 

[BNEFlyer]

I cancelled my flight a few months ago and it was credited back but I still don't know what the expiry date is. A call to Amex would probably tell us.