An estimated 3,000 people, including several hundred Britons, are unable to leave the country after protesters took over Bangkok's international airport.
Anna Glover, 26, has been travelling with her sister Emma, 28.
They were due to fly back from Bangkok on November 28, but are now unlikely to be home until Wednesday.
Emma now has to spend her 29th birthday in a Thailand hostel.
Anna said: "Nobody is able to even enter the airport. The Thai people do not talk about the issue in case they offend the government.
"It is all a bit scary and we are having to travel overland to get home instead.
"Singapore airlines have not answered their phones for days. They are paying for us to stay in a hotel but we are having to pay for additional flights out of our own pockets."
All flights in and out of the Bangkok airport were cancelled after the People's Alliance for Democracy took over the building — demanding the resignation of Thai prime minister Somchai Wongsawat.