How do I get 3G Service enabled on my 3GS?

Hi everyone,

Here's the story: I purchased an iPhone 3GS with an Optus Pre-Paid deal (with 3G included) many years ago. My Optus contract finished and terminated.

I started a new business contract with my fathers company Telstra Plan with a new non-3G enabled plan. I recieved a new simcard and everything worked (other than 3G ofcoarce).

The Telstra Business Plan has been completed and I have re-entered a new contract period with Telstra again. But this time I have organised 3G to be enabled.

The plan has commenced but 3G doesn't actually work. I have unlocked my IMEI number through Telstra and I was told to Sync my iPhone. I completed the sync and I still don't have any 3G capability!

Can anyone recommend a way of getting the service enabled properly? I have tried the Telstra website to send me the settings (it also didn't work).

Any help will be greately appreciated! Thanks.

P.S. everything is 100% legitimate, I promise!