When Delta changed my flight by four hours, it created a major inconvenience. It was my departing flight for the end of a two-day job interview, and I absolutely could not work with this change. Cancelling the flight was a hassle, but I eventually cancelled it, and the customer service representative assured me I would receive a refund in 7 to 10 business days – since Delta had drastically changed my itinerary.

When I asked for a confirmation number for the refund, she said it would be the same as my ticket confirmation number. I was cautious enough to postpone purchasing a new flight until my refund came, but I still expected to receive my refund in the time she told me.

Two weeks later, I still hadn’t received a refund. I called again, and this time a new representative snapped, “Your flight was nonrefundable.” I interrupted and explained what had happened. She checked, realized that I had never been given the promised refund, and assured me that it had now gone through and that it would be credited to my bank account in 7 to 10 business days.

A week later, I still didn’t have the refund. I knew that it was technically still less than 7 business days since my most recent phone call, but I was taking no chances. I called again and waited thirty minutes before speaking to a representative, who once again assured me that the refund was on its way. This time I asked for the representative’s employee ID. He told me he didn’t have one.  I don’t know of any other major company where that would be the case.

So I emailed a complaint to Delta. I told them that they were unlawfully withholding my refund after I had to cancel my flight due to their error and that it was just unscrupulous business to not provide confirmation numbers or employee IDs so that an employee would feel accountable for telling customers the truth. Then, knowing full well that I didn’t have much power as an individual, I added: “If that money isn’t in my bank account ASAP, I will contact my credit card company and let them hold Delta accountable for its dishonest business practices.”

The refund showed up in my bank account the next morning, even though it had only been five business days since my second phone call. You can tell me that it had nothing to do with my threat, but that’s too much of a coincidence for me.

How did I know that the credit card company threat would work? Well, a friend of mine told me that a European hotel tricked her into letting them run her debit card multiple times. The hotel owners first said her credit card wasn’t working so that she would give them her debit card, because they knew that her credit card company would simply refuse payment when they saw how many times the charge had gone through. Her bank didn’t have the power to refuse payment on debit charges, but they would have had that power on credit charges.

Since hearing my friend’s story, I’ve switched to paying with my bank credit card instead of my debit card. This tussle with Delta was the first time I saw that decision pay off, but I’m more determined than ever to protect myself from sloppy (and unscrupulous) businesses. I don’t recommend that anyone fly with Delta – I’ll certainly be avoiding them at all cost in the future. If you do fly with them, play it safe and pay with a credit card. Then, if they promise you a refund, make sure to call back five minutes later and ask a new representative to verify what the last one told you. Otherwise you’ll never know for sure.