Pantech duo i did the same thing and i dont know how to fix the invalid card issue as far as a puc code...

PUK
code, (personal unlocking key).



This is SIM card related / specific. If you take the SIM
card out of the phone, the phone will work with
another sim card.



The puk
comes up when the pin code has been entered wrong 3 times. To get the puk
code for your sim card, you have to call the service provider of that
sim card. They are the only ones who can provide you with the right puk
code for that sim card.


The puk
code may also have came with the documentation of the sim card, if its a
prepaid card the Puk code

comes on the documents or on the box of the product.



if your unable to obtain the PUK
code, get a new SIM card.



Also entering the puk
code wrong too many times will eventually ruin the sim card forcing you
to buy or contact your service provider for a new sim card.


There are no puk
code calculators or anything that we can do about it, you can buy
premium assistance and you will get this same response. There is
no other solution.


You have to contact the phone service
provider of that sim card or replace the sim card.
PUK code, (personal unlocking key).

This is SIM card related / specific. If you take the SIM card out of the phone, the phone will work with another sim card.


The puk comes up when the pin code has been entered wrong 3 times. To get the puk code for your sim card, you have to call the service provider of that sim card. They are the only ones who can provide you with the right puk code for that sim card.

The puk code may also have came with the documentation of the sim card, if its a prepaid card the Puk code comes on the documents or on the box of the product.


if your unable to obtain the PUK code, get a new SIM card.

Also entering the puk code wrong too many times will eventually ruin the sim card forcing you to buy or contact your service provider for a new sim card.

There are no puk code calculators or anything that we can do about it, you can buy premium assistance and you will get this same response. There is no other solution.

You have to contact the phone service provider of that sim card or replace the sim card.