Instead, Thomas found himself driven through the night on dirt roads, deep into the jungle. "I suddenly realised the danger I was in and jumped out of the back seat, and rolled on to the ground, knocking myself nearly unconscious. They all got out and surrounded me. It looked like it was going to get really nasty so I took out all my money - which was about 20 [$39] - and handed it over. Then they just left me where I was and drove off."
What followed was a seven-hour walk through fields and farms, stalked by feral dogs, before he made it to a shop where he collapsed, severely dehydrated. Here the alarm was raised and Thomas was driven back to his hotel by a man on a scooter.
"I reported it to the staff there and they told me it sounded really strange, and that nothing like that ever usually happened. But when I mentioned it to other expats they told me it happened every day. There were stories of people being tied to trees and robbed and so on."
Among such horror stories are also tales of murder. In January 2013, 22-year-old City trader Stephen Ashton was shot dead at a New Year's party on a Koh Phangan Beach, caught in the crossfire of a gang gunfight.
Police are hunting the killers of Hannah Witheridge, 23, a university graduate from Great Yarmouth, Norfolk, and David Miller, 24, from Jersey, after they were attacked with a garden hoe while walking home from a late-night party on the island of Koh Tao at the weekend. Their deaths take to 13 the number of British visitors killed in Thailand over the past five years. A reporter on the Samui Times, an online English-language newspaper, said yesterday that there may in fact be more: the authorities are so anxious to protect the country's reputation as a dream holiday destination that unexplained deaths of Westerners are often branded suicides and not properly investigated.
In addition to the murders, on its website the Foreign Office points to "vicious, unprovoked attacks by gangs, violent assaults and robberies, sexual assaults and reports of people having their drinks spiked".
All this in a holiday destination that has attracted four million British visitors over the past five years. Ever since the publication of Alex Garland's novel The Beach two decades ago, the islands of Thailand have become a parable for our globe-trotting times.
Koh Tao is the smallest and most remote of the archipelago's three islands. It is seen as a relaxing outpost where tourists can laze on the beach or enjoy a spot of snorkelling or scuba diving. Even the party at which Witheridge and Miller spent their final evening was a quiet affair by Thai resort standards. There were no more than 50 to 60 people dancing, with a handful of fire jugglers on the beach. By 1am, the party had come to a close, so the pair walked down the dark beach towards the Ocean View hotel. Their bloodied bodies were only discovered when the sun rose.
Yesterday, fellow travellers on the island lit around 100 candles and joss sticks on the beach where the Britons were killed. The prompt arrests of a number of Burmese migrants are seen by some residents as a token gesture to the watching world.
British expat Clare Plunkett, who has lived on Phuket for the past five years, says she steers clear of the party area of the island, and neither she nor her family have ever once felt threatened in the time she has lived there. She has noticed a changing attitude in the Thai people towards foreigners and a growing clash between a conservative Buddhist culture and the worst behaviour that Western hedonism has to offer.
Despite its strict drug laws, Thailand's beach parties are fuelled by Ecstasy, magic-mushroom pizzas and everything in between. An explosion of yaba, a mixture of crystal meth and caffeine whose name translates as "crazy medicine", has recently been reported among the locals. Westerners, meanwhile, wash down everything with cheap alcohol.
Charles, a 27-year-old who runs his own events company in London, recalls the sun rising on one such party in Koh Phangan. "There was this English couple who were having sex in the water, which was obviously incredibly disrespectful to the locals, but everybody went nuts. One Thai guy ran in there and just started attacking the man, then about 20 others followed and beat the absolute hell out of him, to the point where he was lifeless and face-down in the water. These Thai people came and drove a pick-up truck on to the beach, and then they just threw him into the back of it and drove off.
"Mainly I experienced Thai people to be very nice, but on the islands with these hordes of Westerners coming over with no interest in culture at all, things can get pretty violent."
Others describe the scene as similar to any 18 to 30 trip on Rhodes or to Magaluf.
Travel writer Michelle Jana Chan says the latest horror story, no matter how appalling, will do little to dent Thai resorts' reputation for unbridled hedonism: "I don't think it will hurt business or tourism. These young people are at an immortal age, where you don't think it will happen to you."
Still they come. A once untouched wilderness is now a global party destination, its pristine sands another murder scene.