Temp card convert into OneVanilla?

So I have purchased these temp MVD cards in the past when other cards were not available, called the # on the back and without having to give any personal info, I have been able to convert this to an OneVanilla gift card. Has anyone successfully been able to then get a PIN for the card, once it is converted to a gift card?

If this worked this would help with MS after all my BB limits were reached and other methods are at max capacity...$4 vs $5 for the price of One Vanilla GCs...