W52P - Handset Region and Codec

[CHERALEE]

I have been trying to connect my new handsets to my Optus VoIP Account, and it is becoming very frustrating given both the Yealink Supplier and Optus said that the phone would work with my service.

I am not 100% sure if these issues will make a difference, but:

My handset under the Status Options states that the Area is Europe, how do I change it to Australia?

Also, Optus Codec is G.711a and G.729a and these options aren't available in the Yealink Web Interface how do I add these?