When calling from an optus mobile (0401 151 XXX) to a local number (9113 XXXX) the call fails with a recorded message: "We advise calls to this number not currently available from your service. Please contact your service provider for further information.".
The call does connect if I use the NSW prefix (02 9113 XXXX) when dialling the same number. This behaviour is incorrect.
That happens to be sometimes as well. I just put the prefix in and it's fine which it sounds to me is the same for you. What's the problem?