[mothered]

So I've used my CC for a few SE's and they probably caught on, hence they want to confirm my address.
I've created a new account with a VCC instead, however they have not dispatched my order or taken my payment, which leads me to believe they will send the same email in the next 24 hours. As that's what happened with the CC order.

I'll update you if they contact me

Now It makes sense.

Please do so- keep us updated.

Yep, I received the exact same email today for my VCC.
Could this have happened because I put the same phone number, or is it because of the VCC?

It's looking like GC balance might be my only option :/

It's because there's Identifiable Information linking both accounts that differ between the two.

They need to establish the authenticity of your accounts, hence the request of credentials In their email. Not that It should be your VCC (you can use any payment system you want), but that may be part of the equation.