Sue,
For this to happen twice to you is totally inexcusable and unacceptable. You have jumped through hoops to get your vacation arranged - twice, only to have it fall apart through no fault of your own.
How could anyone who owns or runs a legitimate business conduct a contest and make someone go through such misery to redeem their prize? Someone needs to be held accountable and see that you are justly and fairly rewarded all ready! It's time to once again contact the people you contacted the first time around and tell them you've had it with all this nonsense. And..keep contacting them until they give you your due!