I am a grisly old goat, who has travelled a fair bit, so I would have found a way to inform the authorities at the airport. I might even have found a way to slip a note into my passport to the effect that I was being forced to carry drugs.
But I am not a 19 - 20 year old who has been kidnapped and held incommunicado for a over a week and, unbeknown to anyone - family or friends - is in a foreign country 5,000 miles from home and has had death threats made against me and my family.
In that situation, if their story is remotely true, I can't say what I would do.