Question: Last year I bought two tickets on SkyEurope Airlines from Prague to Barcelona through the carrier’s Web site using my credit card. The purchase was confirmed and SkyEurope listed the transaction as “pending approval.” The site promised to let me know if the purchase could not be confirmed.

However, on the date of our departure, we were told that our tickets had not been booked because my credit card company hadn’t approved the transaction. SkyEurope never notified me that the purchase wasn’t confirmed. I was forced to buy new tickets at the highest walk-up fare, which cost $711.

After I returned home, I called my credit card company to find out what happened. It told me that it didn’t reject the charge. So I wrote to SkyEurope, requesting a refund of $433, which is the difference between the booking fare and walk-up fare.

SkyEurope has sent us form replies with no solution or answer whatsoever. Interestingly, the same credit card I used to purchase my first ticket was instantly accepted when I bought the second ticket. Can you help me get a refund?

– Max Putra, El Sobrante, Calif.

Answer: When you received your confirmation, you had every reason to believe your reservation was valid. SkyEurope should have contacted you directly if it couldn’t process your credit card.

Your problem is becoming all too common, unfortunately. Most airlines now use electronic tickets, which leaves airline passengers with nothing more than a confirmation number and a sheet of paper printed from their PC.

Is that the real ticket? Well, if you’re given a confirmation number, I think it’s reasonable to assume that you have an actual reservation. But your case — and several others like it — suggests that this is no longer a valid assumption. Now, in this world of online booking, you need to call the airline before you leave to confirm you still have a reservation.

I guess when it comes to online reservations, seeing isn’t always believing.

Was this preventable? Sure.

Always call to confirm your reservations and flight departure 24 hours before you leave. Even at that late hour, I think SkyEurope could have fixed this problem. Don’t just show up at the airport with a printout of your itinerary. That’s asking for trouble.

You could also have used a travel agent. A trusted travel adviser would have made sure that your tickets were actually paid for and confirmed. Personally, I would have called my agent for this type of reservation. Although it’s a simple point-to-point flight, it’s in Europe, where the expertise of a professional would be extremely useful.

I think careful monitoring of your credit card statement might also have revealed that you hadn’t been charged for the tickets. I download my transactions from my bank every month, and if a big charge that I’m expecting isn’t there, I usually can catch it.

I contacted SkyEurope on your behalf. It apologized for the lengthy wait and the form responses. The airline checked with its bank and found that because of a server update, your credit card wasn’t processed the first time around. It refunded the fare difference between your two tickets and has wired the money back to your bank.