HTC One M8 is unlocked but still doesn't access service

[AC Question]

I brought my HTC One M8 (or atleast i think it is, it has the Karman Audio) and I told my service(Verizon) that I was moving to Spain, Barcelona, and would like to have it unlocked so I can use it there. They did it but when I arrived and tried to use it I couldn't. I can use Wifi but not call, text, or receive calls. I brought it to a small store and had them unlock it but when I went to pick it back up they told me that it had already been unlocked.
When I put the sim card in it, asks to unlock the sim, I enter the password, the phone thinks for a bit, then the signal has an X above it.
Thanks for the help

 

[B. Diddy]

Welcome to Android Central! Go to Settings>Cellular Networks>Preferred Network​, and see if you can select the carrier there.