Hey Gabo! You can turn off voicemail on your Optus mobile the following ways:
From your Mobile, dial 1509 (free call)
Select the 'voicemail' option
Choose the 'deactivate' option
Or if you're using a Postpaid mobile service.
Use the Optus SMS Menu, by texting the number 8 (eight) to 9999
Reply with the number 1 (one)
Follow the remaining prompts
For more info on Optus voicemail, please see our page here.
THE MENU AT 9999 Doesn't have the remove voicemail option any longer as of june 2018
you need to create a profile at https://www.optus.com.au/customercentre/myaccount you will need a valid email address to be set a confirm profile creation code,
once that is done, go to your dashboard, select "SETTINGS" AND CLICK "VOICEMAIL SETUP"
here you can change it. as well as diverts, no answer, and phone in call and out of range options .
this goes for coles pre paid mobile also
calling the 1509 (freecall number) will return an Optus Menu link via text
in the optus menu as someone stated above to type 8 to the text number does not work any more
returns a "the key you entered is invalid" response,
in the optus menu there is nothing available to change Voicemail any longer
calling 321 and following prompts does not have the option either to deactivate or turn off Voicemail
texting or calling 1509 Voicemail on or off in contacts list no longer works either.
optus have changed the menu options
best go online and create register a profile
simplest and easiesr way, otherwise your just going to go around the world in frustration as all these help posts no longer work
go to create your profile online at https://www.optus.com.au/content/optus/en/registration
select Create Register, fill in your details, get the confirm code sent to your email
then you will have created a profile,
on your dashboard select "SETTINGS" on the right blue options wall
then VOICEMAIL - [setup]