I cancelled my Qantas FFP redemption booking on 14 April 2020, got the points in on 01 May 2020 and the taxes in my credit today, 12 May 2020. Satisfied with the process.

Will receive email from Qantas Customer Services 3 days before the taxes are in about refund:
Hello vsepr,
This is to confirm that the requested refund for booking reference XXXXXX has been processed back to the same form of payment that you used to make your original purchase. The nominated bank or financial institution may take some time to process the funds back to this bank account.
If you requested a refund for a booking made using Qantas Points (e.g. a Classic Flight Reward or Points Plus Pay- Flight booking), please allow up to 10 business days for the Qantas Points to be credited to the nominated Frequent Flyer account in accordance with the Terms and Conditions of the fare. The monetary component has been processed back to the same form of payment that you used to make your original purchase. The nominated bank or financial institution may take some time to process the funds back to this bank account.
Thanks,
Qantas Refunds Team

Let's compare the refund experience from Qantas and the airline that prides itself as the "World's Best".