Get breaking news alerts and special reports. The news and stories that matter, delivered weekday mornings.

It was a booking mistake off by one letter but nearly 4,000 miles.

When a North Bethesda, Maryland, dentist planned a trip to Portugal for a conference last September, he decided he'd quickly swing by Granada, Spain, to see the famed Alhambra and other historical sites.

But carrier British Airways had other ideas, and instead sent Edward Gamson and his partner to Grenada — with an E — in the Caribbean, by way of London, no less.

Gamson, who said he clearly told the British Airways agent over the phone Granada, Spain, didn't notice the mistake because his e-tickets did not contain the airport code or the duration of the trip. It was only 20 minutes after departure from a stopover in London that he looked at the in-flight map and asked the flight attendant, "Why are we headed west to go to Spain?"

“His response was: 'Spain? We’re going to West Indies,' ” Gamson said.

After nearly three days of transit, Gamson just barely made it to the conference, but his vacation was ruined: He's out the more than 375,000 frequent-flier miles he had used to book his first-class tickets, and he said the airline was less than helpful.

Let our news meet your inbox. The news and stories that matters, delivered weekday mornings. This site is protected by recaptcha

Sign up for top Travel news direct to your inbox.

British Airways offered him and his partner $376 each and 50,000 miles, Gamson said. But he figured the pre-booked hotels, trains and other tours they had planned cost upward of $34,000. So he sued the airline, and he's representing himself.

"I have no legal background; I’m a dentist, but I know right from wrong — I don’t know if that does you any good in this world," Gamson told NBC News.

"I really thought they would just want to settle with me, because it’s so apparent that it’s just a stupid mistake," he said.

But British Airways fought back, first trying to get the lawsuit moved to a federal court, where international aviation rules apply, and then trying to get it dismissed completely.

Michelle Kropf, a spokeswoman for British Airways, said, "As this is active litigation, we are unable to make any comment at this time."

The lawyer representing the airline did not return calls for comment.

"This was a long awaited vacation that didn’t happen."

Earlier this month, U.S. District Judge James Boasberg denied British Airways' request to have the case moved to federal court, saying that it was an issue with booking rather than the international travel itself.

In a humor-laced, eight-page ruling, Boasberg noted the case highlighted the Mark Twain saying that the "difference between the right word and the almost right word is the difference between lightning and a lightning bug."

The flight crew was very accommodating and tried to help as much as possible, Gamson said. He said they told him the same thing had happened a week before. But the original crew had to disembark at St. Lucia, and when Gamson and his partner got to Grenada, he said support staff on the ground there were less friendly.

“This was a long awaited vacation that didn’t happen,” he said.