I have a Samsung Focus S, locked to at&t, and I'm having a problem trying to unlock it. I got a code from at&t, and I tried to insert a foreign SIM card to prompt it to ask for the unlock code, but it does nothing. I also tried to enter a combination of numbers I found online that should have forced it to ask for the code... still nothing. All it says when I do that is "Phone Failed". Does anyone have any ideas? The phone is a refurb from at&t and it is running Windows Phone 7.8. Any help would be greatly appreciated.