I called BA on Tuesday 14 April to cancel a flight on 19 April. Held for less than 20 minutes. Avios returned within 24 hours and money back on my card by yesterday (Friday).
No complaints but I have been sitting on the refund call and hoping that most of the expected surge had passed. Did try about a week earlier but constantly cut off due volume of calls.
(not a regular poster as you can see but posted for balance)