Telstra Maddington Store

I want to upgrade my mobile phone to my currant pre paid account. how do I  do thatI will need a new phone and sim card 

Do you sell these at either your store or another Telstra store?

I am on the $35 Go Mobile plan and would like to upgrade my phone to the iphone 5s on the same plan which you have for $55/mth.  I cannot wait the 2-4weeks to receive one.  Do you have any in stock, and if so do I need an appointment with you?Thanks ...