I'm not a huge fan of Haiku so I might be wrong here, but isn't the idea of Haiku supposed to be taking two strong images and making a clear cut between them whilst adding a sort-of-link? I could well be wrong, but to me this seems like more of a sentence from the opening of a story to me rather than Haiku. I do like the idea that you're using, but perhaps try to add more defined images than Santa and the children that he's delivering presents to as your main focusses since they pretty much belong together without thinking about it so it's difficult to make a clear cut between them - maybe something like comparing the children to spirits or similar? It's up to you haha.
Also the syllables don't really fit for a classic Haiku; I think you've used 5/7/5 words here rather than syllables. So for example if you changed "San-ta could not make it" (6 syllables) to something like "San-ta was not there" (5 syllables), that'd be a better fit to the structure of Haiku. The amount of syllables you use in Haiku isn't set in stone that it has to be 5/7/5, but maybe it'd make it seem a bit more like a poem if you experimented with this structure. It's just that the 6/12/6 structure you're currently using makes it seem pretty wordy for a Haiku when they're meant to be more clear-cut and sharp. It's a good effort and a nice concept, but there's a few points above to consider - I'd love to see more in future! :)