Hello beings more technologically advanced than me (which pretty much covers everything on planet Earth all the way down to my pet tortoises)...

My Samsung GT-S5511T mobile phone displays this message when I put my new SIM card (from another network in):

"Phone Freeze. SIM Unavailable"

Oh... Err... Any ideas what to do?

Many thanks in advance...

Maybe get it unlocked from its current carrier?

Ah, maybe I should have been clearer.

It's from a Australian network (from when I was working in Australia funnily enough) and now I am back in the UK.

So, my question was: how do I get unlocked as I can't really contact the original network and I don't really want to pay one of those dodgy websites...

(In fairness I thought that that was the point of helpful forums like this, to avoid being ripped off! )