iPhone 4 unlocked but still displaying 'Invalid Sim'

[Anonymous]

Hello.

I recently inherited an iPhone 4 from a friend as she has upgraded to a newer phone and no longer needed it. She had the iPhone for 2 years on an o2 contract, but the contract ran out before she gave the phone to me. I purchased an o2 Pay as You Go sim for the time being and then asked o2 to unlock the phone so I could go back to using my T-mobile SIM card in it. I received an email and text message from o2 just over an hour ago saying the phone had successfully been unlocked, however when I put my T-mobile SIM into it and synced it with iTunes, it continued to display the message "The SIM card connected in this iPhone does not seem to be supported".
Can anyone help me with this? Should I just wait a while to see if the SIM works or has something gone wrong?

Thanks.

[Liquid]

You can check here to see what it says.

http://www.imei.info/

[jonsie]

Call customer service or use the online chat to advise them the phone is still locked. They will rearrange the unlock for you.

[Anonymous · Accepted solution]

I would give it 24 hours before doing anything as getting a text/email is not a definitive answer for it being a done deal. 

[Anonymous]

Thanks everyone. I tried all your suggestions but I think iTunes just took a while to register that it had been unlocked. I connected it just now and it restored perfectly and is now working on another network.
Thanks for your advice!

[Anonymous]

I had exactly this issue!!! I got the text message that the unlock was successful (12 mins after getting off the online chat) so switched the sim in preparation for connecting it to itunes.

I immediately got the "Sim Failure" notification and "Invalid Sim" appeared in the top left.

So I thought, crumbs and connected it to itunes. Still no joy, no message of congratulations just the phone connecting to itunes. Waited a couple of minutes and nothing changes, went through the set up?? even though the phone was active, no change.

So I decided to restore, which, while it takes a while proved to be a good thing. restored firmware etc. set up as a new phone and at the end of it I get the "Congratulations" message and set up the phone again.

Carrier display appeared and connected to the carrier service, so all good.

So, be patient and it will all work out fine.