My golf caddy ended up in Dubai on the same scam about seven years ago. Her passport was confiscated but she had her phone and was able to communicate on Line.
She refused to provide the required services, but by all accounts was treated humanely.
She and two friends that went with her spent days contacting family trying to raise the funds to buy them out of the supposed contracts. I can't recall the exact amount, I think in the region of 500K Baht each.
I recall thinking at the time that as the amount was 10 times more than the cost of airfares and accommodation, that the scam was actually kidnapping for ransom, and not about prostitution.
Anyway, they all managed to raise the money from friends and family after about two weeks, and was back on the golf course, telling me she was inquiring about going to Korea.