A friend of mine had the same experience when his gf was going to Thailand for a couple of weeks. I had made the booking for the flight for my friend as he had a problem with credit cards.
The refusal to let her fly was that of the immigration officer not the airline, she had in fact checked in and was stopped after that
I was able to get over the problem by faxing a letter to IB saying I would be responsible for all her expenses. It was of course not true as I was in Spain. She was able to fly out the next day although of course there were some additional expenses.
