I'll keep trying online then, if it worked for you. Are you flying after June 30th? I'm using the same CC they have on file that I used with them 2 weeks ago, and there aren't any issues with it that I'm aware of, so not sure why I'm getting the error message (other than trying to use an invalid coupon!) It's odd to me because when I try to use the codes that expired 2/28 it tells me they're invalid - won't even apply the $10 off - but with the newer code it shows the $10 off of the price, yet when I go to the final step to "book now" I get the error.
I know I know, you can't get something for nothing....just wishful thinking...