After buying the Samsung Galaxy A20, Ozbargain's Best Budget Smartphone (Under $300) in 2019, I was looking for an unlocking solution since it was a Vodafone model. I PM'd the fonefunshop rep and they were able to offer a 10% off coupon for OzBargainers upon check out. Original price is already competitive at £3 but with the coupon, it comes down to £2.7 (about $5.20 AUD). Note that the unlocking software requires Windows (no Mac/Linux support).
For further details on how this works, refer to rep's comment. Previously, rep also posted guidance here.
Note: It's worthwhile checking if your phone needs unlocking first at the Vodafone handset unlock self-service as I was about to buy this when I realised the Vodafone website mentioned my specific phone was already unlocked! I'm sharing this deal as I messaged the rep asking for an OzBargain code, and whilst I didn't end up needing it, I wanted to share it with the community.
EDIT: Turned out the Vodafone website incorrectly identified my Big W Vodafone Samsung Galaxy A20 as unlocked. It wasn't, and there wasn't a way to unlock it through Vodafone. I ended up paying the $5.20 or so to FoneFunShop, and it's unlocked my A20 as promised. I tried running the software in W10 Sandbox mode and it didn't work, but when I ran it in normal W10, it worked fine. For those wondering how long it takes, it took about an hour between when I ordered and when I got the activation/licence key (8:30pm on a Saturday night) - but keep in mind these guys are UK based so I believe if it's their night time, they may take a bit longer to send out the codes.
Thank you. I just bought one but could not unlock my Galaxy A20 due to the unlock code "00000000" is incorrect. I have sent an email to you for further assistance. Thank you.