Exactly the same has happened to me. I managed to speak to an advisor this morning who was polite and initially helpful, but when he transferred me to someone 'who could help' the connection was cut.
I suspect the problem (code rejection) is because it is for an old keypad phone, but for a large company making big buck profits this is totally unacceptable. I think the worst thing is the difficulty in contacting any form of useful support; I'm sick of being sent round in circles and am ready to leave VM.
I later googled reviews for Virginmobile and surprise surprise: 1/5 stars!