(adsbygoogle = window.adsbygoogle || []).push({}); just bought an iphone 3gs second hand and it dont detect any sim cards i phone o2 its a blocked phone and i dont want to take it back i just want it unblocked

you can't unbar it unless the original owner calls in and gets it unbarred for you.

Sounds like a stolen phone or someone has reported it lost and sold it on to you. If it is barred then you have yourself a very expensive BRICK