Refund Advance is a loan based upon your anticipated refund and is not the refund itself. Just to clarify, you received an email stating that you were approved for the Refund Advance card before you applied for it? Please call 1-888-285-4169 so that they may answer your questions directly about the email you received.
https://ttlc.intuit.com/community/refunds/help/about-the-refund-advance-application-process/00/25557