how do i obtain a PUK code for my Ipad (and yes that is what my Ipad is asking for)

I own 64bit Ipad. One day I turned it on and it said "Enter a PUK code". I don't have any idea what this means, I just know my Ipad has been inoperable since.

There is no carrier, it's not a phone. Just Wi-Fi. I have wasted SO much time trying to get this resolved I am ready to throw this thing in the drink. No help from Apple, there is no "carrier", so ***????!!!!! Feels like a $900 rip off right now. I am not a general Mac or Itunes user, bought this Ipad as an experiment for EHR in my medical office, where it could have been a very handy tool. I don't want to loose all of the medical information already downloaded, and Itunes doesn't recognize it when I plug it in to my laptop.

I have removed the Sims card, then the picture of a USB cable pointing to the Itunes icon appears. Itunes and the Ipad don't seem to recognize each other from the same device that I've updated on before. Any help would be greatly appreciated.

I'm really upset that Apple wants to charge me to tell me how to fix it, when it was as simple as me turning it off one day, and getting this message the next, ya know???!!!!

Lisa