The most likely reason the gift certificate order you requested cannot be completed yet is because we do not have all the information we need.
In order to move miles or points out of one of your Reward Programs (in this case, to Redeem for a gift certificate), we have to know the details of your account in that program. We refer to this as registering your program (or account) with us. To register a program you belong to, collect the information that describes your account in the program. (This could include a password or PIN, an account number—the exact requirements differ from program to program.) When you've got the information, click the link "Register this program" (from an e-mail, your loyalty wallet or your My Account page) and fill in the form.
Once you have registered the program and we have confirmed the details of your account in the program, your order will go ahead.
As well, your transaction may still be processing/pending. You can check this by clicking on My Account and reviewing your Transaction Details.