Availability:
Telstra - In Store & Online Chat (New, Port-In customers only)
JB Hi-Fi - In Store (Details here, thanks nismo)
Mod: The above information is gathered from reps. Note that some existing/upgrading users were able to obtain the deal via Telstra online chat, however from what we've been told they aren't authorised to offer such a deal so don't expect to receive this.
Mod 2: Users purchasing in store (not online), have reported receiving a bonus pair of earphones. Thanks KLoNe
If you have successfully claimed this offer please share your results as to where / which store you successfully purchased from.
Got it from Telstra Subiaco. $59 with earphones and Google Home Mini. Live chat also honored and gave me $10 off for a total of $49 per month. Didn't try for the extra 5GB as I don't really run out and not too keen on pushing live chat even more.