Optus aren't going to contact you because your post was made via a public forum. Besides, Optus you can't contact Optus via email.
You should be able to get at replacement SIM from an Optus store.
Other alternative contacts a via messaging in the Optus app or via private message on Twitter or Facebook.
Hi, need to correct you there, Optus has blocked private message via Twitter. Don't know about FB
Well if they have they haven't stated that publicly (at least nowhere in this forum that I have seen) and they still say contact them via twitter and facebook.