Finally, I got it to unlock the phone properly.
This is what I did:
Flash the LG CU500 by using CU500_UNLOCK.sex
If your phone don't restart by itself then you will have to manually restart it (very important). Plus, you have to do it within the time frameAfter that I flash the phone with NV_CU500.nv2 file.
The phone working good now. Thank you very much for your time and help, .:hack3r2k:. and other members.
Hope this will help other member(s) that have problem unlocking the phone.
Time needed - 00:28:08