British human rights worker Kate Burton, who was kidnapped with her parents in Gaza last week, has told how she "lost it" with her captors.
Ms Burton, 24, told BBC News she initially remained calm but became "nervous and angry" as promises to release them were not acted on.
The human rights worker denied claims she had not helped the investigation into the identity of the gunmen.
Ms Burton has vowed to continue her work in the Middle East.
Ms Burton, her father Hugh, 73, and mother Helen, 55, who is known as Win, of Newbury, Berkshire, were released unharmed on Friday after being held for two-and-a-half days.
Ms Burton said she had been well aware of the situation.
"You are surrounded by these three armed men with Kalashnikovs in their hands and there is no point in kind of getting angry or scared or nervous.
"I know Gaza quite well, I know how these kidnappings work and, indeed, these people often have kind of petty demands and I knew it would be one of these things and it would just be a matter of time and we would probably be released."
But Ms Burton said her emotions changed as captivity dragged on.
"You don't believe anything your captors are saying any more," she said.
"So I think I just kind of lost it and started shouting at him and saying 'Why are you doing this to us? What do you want? Why don't you give us our freedom?'
"He was getting angry and shouting back to me, you know, it was a pretty tense moment.
"That was just at the end before we were about to be released."
Ms Burton has said she believed their captors felt they had no other option, though they knew they were doing wrong.
She said she felt a "sense of guilt" about putting her parents at risk but did not regret taking them to see the "positive side of the Palestinians", she said.
She has vowed to continue her work in the region, but may move from Gaza.
In an earlier interview with the BBC News website's Martin Patience, Ms Burton urged aid workers to remain in Gaza.
"We must not turn our backs on the Palestinian people," she said, speaking from the West Bank town of Ramallah.
Their captors made a video shortly before freeing the family
She said the strength of the Palestinian people had inspired her "more than anything else in my life".
"There's something quite amazing about the people in Gaza," she said.
But at times she feared for her life, she said.
"If the kidnappers were negotiating with people and things weren't going their way you could feel the tension in the room. I know that Palestine isn't Iraq but there was always that small doubt that things wouldn't work out. "
Ms Burton, who grew up in Belgium, added she was also fearful the Palestinian Authority would stage a rescue operation that would go wrong.
Ms Burton, who speaks Arabic, said two main kidnappers, both of whom were critical of the Palestinian President Mahmoud Abbas, remained with the family.
They said they had carried out the kidnappings to highlight issues such as Palestinian prisoners being held in Israeli jails.