That might not even be a problem on their end, but with your prepaid Visa bank. I've used a few different ones, the one I had the most trouble with was from Vanilla Visa. Shit card.
Not that I get them anymore, but if I needed to, and for anyone else out there, see if your bank does prepaid Visas. Mine, TD Bank, does them with no activation fee (you give them $25 they give you a $25 TD Visa card), and since it goes through that specific bank and it's registered to you there, there shouldn't be any problems using them (I didn't when I was doing it). Just usually need to hold some sort of account with that bank.