I had a J flex booking and rang QF to cancel. No problem getting through, no attempt to dissuade me from a refund. Was told the refund will take 'up to 8 weeks'. The CSA was very pleasant to talk to.
I had deliberately booked J flex even though it was more expensive than other fares on offer which were cheaper but not refundable. Along the way with the booking, when timing changes needed to be made by QF, there was quite a lot of pressure from QF to switch me to a slightly cheaper J fare which they described as giving me a partial refund - they omitted to mention I would lose the fully refundable aspect of the fare if I got sucked in by that. So watch out for that if refundability is important to you.
Before deciding to cancel I had attempted to change dates via the QF website MMB. I got annoyed when each individual sector was shown for flex fares as -$14 or -$16 or similar small refund amounts, but when I got to the total calculation it would never give me a refund figure of ~$30 but would always default to me having to pay an extra $2. Every single time. So I just gave up despite it being a DSC booking. I absolutely hate nickel and diming on expensive purchases
So I cancelled because of the combination of that, the constant bubble pauses (it was my second cancelled trip due to bubble issues), and the NZ negative covid test requirement which adds an extra $150 for each pax and is a pain to organise.
So now I'm wondering what happens to all the FF points I earned through making my bookings on my credit card - do they disappear when the refunds get processed?