I found the following articles about BA deliberately blocking online cash refunds for Avios bookings and there is a Chrome workaround for that. It also states "If you ring British Airways, you WILL receive your cash refund."
Here are the links which maybe useful for some people:
https://www.headforpoints.com/2020/03/19/british-airways-refund-avios-booking/
https://www.headforpoints.com/2020/...line-avios-flight-refund-using-google-chrome/
Thanks for that. Had holiday booked for Canada next month, but they're planning to close their borders & no word from BA yet. Already out of pocket with a flight to Aberdeen next week that I'm not going to.