Well, yes, BA's IT has always been poor - which is not helping them right now. Processes which have to be done on the phone, like cancellations and even use of the so-called vouchers, would considerably help BA themselves if they could be actioned online.
In answer to your points at post #13 - yes we have had cash back but only after some time and a bit of further prodding - all of which adds to their already overloaded contact centres. We have had cancelled avios flights (which are cancellable anyway) where we have had to chase up the cash portion of the refund, and we have had a 'holiday' (ie a package of flights plus hotel) cancelled back on 21 Mar for which we have only just had the refund - so it is very variable but the advice over on FlyerTalk from the experts, and even some BA staff who have contributed, is that you will get it but it may well take a lot more time than normal - where normal is not always quick!
As for bookings staying on the system, I was more concerned about being treated as a no-show and/or appearing to security systems as planning to travel, against the restrictions that are in place. One of our flights was to the US and there are reports of people having their ESTAs cancelled, apparently because they still appeared to be travelling despite the flights having been cancelled.