Not receiving verifacation text to set up optus as a payment option

Could it perhaps be a delay due to your mobile network connection? It has happened to me often. You could try again later if it is, in fact, the delay, otherwise, you could contact Microsoft Support.

You should try contacting Microsoft Support to see what's up with this.

That would indicate that your Xbox Live account was set to the United States when the account was created. To resolve this, please migrate your Xbox Live account region to the region you're physically located in using our
Region Migration Tool.

Let us know how it goes!

You can use paypal. I've got it set up on my account. Try adding it at
https://commerce.microsoft.com

Thanks for letting us know, rhymak!

For this particular case, we'd recommend reaching out to our
Chat or Phone support teams specifically - they'll be able to look into your account directly and securely with you to help set that up and make sure your payment and billing info is squared away on their end.