Okay, so i'm on the same operator as matt austin is (Virgin Mobile). I've checked their coverage map and 4G is available in my whole suburb.

I have activated 4G with Virgin. That's definite

When i switch to 4G there is no network whatsoever. That means there's no 4G symbol displayed, nor an internet status on my home screen. I can't connect to the internet, nor can i even select in settings to connect to the internet

Strange :/