i bought a factory unlocked iphone 4 from england in december, brought it to pakistan and have been using it since. 2 weeks ago, i restored it(no reason…:D). AFTER THAT IT WAS LOCKED! even though i had updated and restored it quite a lot of times before in pakistan without any locking. i called apple and they told me to use an authorized sim card. i ordered a 3 sim card from the uk and itunes unlocked it. but now, whenever i put my waridtel sim from pakistan into it, it goes into the only emergency calling screen!..what's happening here?
Sounds like your phone is locked to 3 and was never officially unlocked to begin with. Only the carrier an iPhone is locked to can authorize the phones official unlocking. In your case that would be 3. Good news is that 3 offers official unlocking. Bad news is that 3 most likely won't do so unless you first become a customer(establish service). Given the elapsed time from when you first purchased the phone, you're out of the 30 day return window. No really good solutions.
apple just sent me an email in which there was a list of carriers in the world, which can be used to unlock the phone. i could've used any sim out of that list.
The process of officially unlocking a locked iPhone is done via the original carrier and the end user should have no contact with Apple through the process. If the iPhone is locked to 3, the contact 3 to see about the first attempt or to have it unlocked.
Generally speaking most second hand iPhones which are sold unlocked are hacked and by updating the hack is removed.
If you did not purchase from an Apple store in the UK you do not have an unlocked iPhone
All UK iphones are locked to a carrier UNLESS purchased from Apple Retail store in person
If you did not purchase in this way then your iPhone was hacked as has already been pointed out
and updating relocks it
You can only unlock the iphone if it is physically in the UK so the native network can see the imei
on the network in the UK