I ordered nbn through a phone call and got the plan I wanted, throughout the call they had me confirm my identity and so I assume they would know my address in their system since I'm currently on a cable plan with them. I get a notification that a technican is coming on x date.. but the address noted in the text is completely wrong, in fact its in a different state?
What should I do now?
Dangerous position to be in. I generally suggest don't muck with the NBN process if at all possible. As soon as you try making changes that's when it gets cancelled, delayed, mixed up, etc.
In this case though it does sound like you need to step in. Its unbclear if Optus or NBN have made the error. Optus are supposed to sort the NBN for you so you can only contact them and request they try clear up what address the NBN is going to use.
Try LIVECHAT (24/7) or Phone on Monday.