If you are on AT&T and have your account online, you can get the PUK code there.

Contact your network customer care. PUK code is given by them.

If your phone has become blocked by mistake, for example you have entered the PIN incorrectly on three consecutive occasions, then you need to contact the mobile phone network operator with your details. To explain a little more, specific to your mobile phone network, use the links above to navigate your way to the specific PUK details for your mobile phone network operator.

my LG Shine, CU720 is locked up i guess. it says i need a PUK code and i have no clue what to type in the box. it also says i have 6 more attempts to try. i need it fixed asap its its a new phone to me and its pretty much my life. so if anybody can help me i would really appreciate it. THANKS