Don’t take any promises made by contest holders too seriously. And don’t take the fact that they wound up picking a different winner too personally. We have plenty of other contests for you to enter.
Remember: Till the time you have not been selected as a winner of a contest, you are not a winner of that contest.
Unfortunately, we can’t force the contest holder to award you the prize. It’s their contest and they can change their mind at any time in the 14 days they have to select a winner.