Hi Rei!
Had a similar experience with yours yesterday, basically I already paid (got confirmation from the bank), however the booking with AIRBNB showed a "failed verification". I directly messaged their main AIRBNB Facebook page with my concerns. Around 2-3 hours later, they replied that they have "located your account and sent an urgent alert to our Case Management team to contact you directly."
True enough, 8 minutes later, when I checked my email, I received a refund notice from AIRBNB, although it did disclose that transaction on the bank's end will take 15 business days.
I also contacted the AIRBNB support in its webpage, and they replied to me 3 hours later as well, stating that: "Your reservation did fail verification, but you will not be charged in this regard. If you were charged, then you will be refund since the transaction was not completed on our end. "
Hope this helps people who face the same problem in the future. Was really scared after reading the bad posts on this topic, afraid that I won't get my money back. Apparently, they reply quickly and because they can trace your transaction (though a "failed verification") they will refund your money as well.