Hmm have a look at the article on the link below and see if that helps.
Edit: I actually posted the wrong link. It should be good now.
Its PUKed!!! Did you put in the pin too many time? Does it ask for a PUK code? Was it active in the first place?
Contact live chat to get the PUK or if you have have the orginal package information, then it should be printed there too.
Hey there izzy072, your phone will ask you on the screen to enter your PUK code when you have SIM locked your phone.
If you mean how do you get your PUK code, go to My Account, click on your mobile number on the dashboard, click on the Manage option and then Show All Settings to see the PUK option.