AirTran shouldn’t have confirmed your ticket if your credit card was declined. And if it didn’t send you a follow-up email notifying you of your card problem, you were correct to assume you had a ticket.
You could have prevented this by doing two things. First, review your credit card statement regularly to make sure you made all of the purchases you thought you made. If you didn’t see the AirTran tickets on your statement, you would have flagged this problem earlier. Also, checking the airline’s site 24 hours before your departure to confirm your reservation would have alerted you to the problem.
As a side note, spam filters can be tricky, so be sure to whitelist the airline’s email address when you make an online reservation. That would have ensured that any emails from the company made it to you. (Again, since you received the first email, it’s understandable that you’d assume that any subsequent messages would make it through the spam filter. But that’s not always how it works.)
If you’re ever in a situation like this, with no valid ticket, don’t panic. Calmly explain the problem to a ticket agent, and if that person can’t help, ask for a supervisor. If showing the confirmation doesn’t work, you should consider doing some last-minute fare shopping. As you noted, Delta would have been a less expensive choice for your trip to St. Louis.
AirTran was acquired by Southwest Airlines in 2011, and has been operating as a subsidiary of the carrier. The carriers are scheduled to be completely integrated by the end of this year, and when I reviewed your case, it looked like this might be a little merger-related hiccup. I checked with Southwest, and its records show that it did, indeed, email you a notification that your credit card had been declined.
“However, it’s clear he did not receive it,” an airline spokeswoman said. Southwest issued you two more vouchers to make up for the difference in fare.