Can you pay for ACT using a debit card?

Hello everyone,
I want to take the December ACT test and have not yet registered for it. On the ACT website’s FAQ (http://www.act.org/content/act/en/products-and-services/the-act/help.html) it says:

"Online registrations must be paid by credit card, ACT fee waiver, prebilled registration voucher, or state voucher. To register using any other method of payment, you MUST use the paper registration folder.

ACT accepts any valid American Express, Discover, MasterCard or Visa card."

I only have a debit card, not a credit card and am afraid I won’t be able to get one until the application deadline. Has anyone had any experience with this? I’m international if that changes anything.