Breast cancer patient Mandie Stevenson was hoping to cross off one item from her bucket list when she booked a flight to New York and filled out her visa waiver form online. But when she accidentally answered “yes” to a question that asked if she was planning to, or had previously engaged in terrorist activities or other related crimes, that kicked off a saga where she ended up paying the equivalent of over $1,000 to have her flight rebooked to a later date.

According to BBC News, the 29-year-old Stevenson, a resident of Falkirk, Scotland, was diagnosed with terminal breast cancer in 2015 and had been planning a trip to New York with her boyfriend as part of her bucket list. As she thought she had everything in order after completing her ESTA (Electronic System for Travel Authorization) form, she was shocked upon finding out that her application was rejected due to her apparent mistake.

Recalling the experience on the BBC show Mornings with Stephen Jardine, Stevenson explained why she mistakenly answered “yes” to the question that asks travelers the following question.

“Do you seek to engage in, or have you ever engaged in terrorist activities, espionage, sabotage, or genocide?”

“I believe I ticked ‘no’ and then when I have scrolled down to click confirm, I think it has nudged and moved. That’s the story I’m sticking to,” Stevenson said.

While Mandie Stevenson thought her error, while “embarrassing,” would be easy to correct, she allegedly did not get much sympathy from U.S. Embassy officials in London, who first told her that the “yes” box next to the terrorism question was the “worst box you could have ticked.”

After going through two interviews and paying £320 ($417) to apply for a full visa, Stevenson’s application was accepted, but that wasn’t the end of her ordeal. She told the BBC’s Jardine that her application would take about three to five days to be granted, meaning that there was a good chance she would end up missing her flight.

Stevenson alleged that the embassy officials insisted that changing the dates of her trip would be her only option, despite the fact that she has breast cancer and has to schedule her vacations on “very specific” dates.

“I live in 12-weekly cycles because I get scanned every 12 weeks. I book my holidays in very specific times and this New York trip was going to be before I get another set of scan results, so I was really looking forward to it.”

All in all, Stevenson had to pay over £800 ($1,042) to get her flight rescheduled for October, BBC News noted.

Reacting to the troubles Mandie Stevenson had to go through to change her flight due to a crucial error on her ESTA form, The Independent travel editor Simon Calder called the terrorism question “completely pointless,” as people who are actually engaged in such activities won’t purposely tick the “yes” box.

“America is completely unforgiving. If that box gets ticked for whatever reason, immediately it’s as though the alarms go off, the shutters go down and you are into a spiral of despair.”

In an article published Friday on the Falkirk Herald, Mandie Stevenson called the mistake she made on the ESTA form the “most embarrassing and silliest thing” she has ever done in her life, adding that she can now laugh about the stressful saga she went through. She also promised to be more careful when filling out such forms in the future. As for the rest of her bucket list, BBC News noted that Stevenson is planning to fly to Canada and Thailand and also hopes to meet former English Premier League star midfielder, Steven Gerrard.