It's done manually by the staff. If they're busy you're not likely to get your embers for a decent amount if time. It took me at least 6 hours for each of mine. So just be patient and you'll get it.
Either the staff are busy (ie: Jubs being away for awhile), your embers wont be rewarded for a bit. They have like a queue for the entrys, so yours might be lower down on the list as many more users entered the contests. Or you can check if your entry was rejected.