You get this message if your PIN has been locked, and you've tried to unlock it using a Phone Unlocking Key (PUK), but it hasn't worked.
If you enter it incorrectly 10 times, your SIM card will be permanently blocked and you'll need to replace it. Each PUK only works with the SIM it was issued to.
You can get a new SIM by chatting to us online.
Once you've got your replacement, you'll need to activate your SIM online