If your Vodafone Subscriber Identity Module (SIM) card is locked for any reason, you need to use the PIN unblocking key (PUK) that came with the SIM to unblock it. Locked SIM cards may not make nor receive calls. Having a locked SIM is not the same as a locked phone. Locked phones are not able to use non-proprietary SIM cards, but may make and receive calls with their original SIM cards inserted.
Locate the original packaging that your SIM came in. The PUK is printed on the sticker attached to the envelope.
Contact Vodafone customer service via another phone or visit the nearest Vodafone store and request the PUK.
Turn on the phone and enter the PUK when prompted to do so. This will automatically unlock the SIM card.