Do you have any information on why Google would block these CC numbers? I know Google, and many others block VOIP phone numbers for example, to discourage rampant account verification, but I can't think of why they would reject a financial reference number.
I imagine it's to stop people from connecting stolen cards to the service and then generating a bunch of other card numbers that are essentially all stolen. It could potentially allow them to use the stolen card more before it was detected.
I have unique/monthly limit cards:
Recently closed one-time cards: Literally, anything that we pay for over the phone or online.One place I'm especially happy to have it is my vet. They're really bad at billing. They've double billed me twice. Now I keep a dead card on file (they want a card) and give them a new one with a hard limit every time I have to pay a bill. No more double billing and I can see when they're screwing up.