I made a new Google account, added my VCC to it and tried to buy packs to refund them via my Google acc, but I keep getting this error:
"Transaction has failed" with a link to more general information..
I made more refunds with the same Hearthstone acc, maybe that's whatsup?
I really don't know why it fails, did some refunds 3 days ago with another Google account and with a different payment method but same Hearthstone acc, maybe Blizzard did something?
You got it locked probably, I don't use that method but know a guy doing it and he got the same error due to his IP. Just try with a brand new account. Keep in mind you can't really abuse it too many times and have to take some breaks.