@deadgirl Hey, I’m sorry for your disappointment.
Really, it’s not you. They probably had their fair share of legacy, minority applicants and decided this year they wanted to emphasize students from a specifically under-represented geographical region (we need more people from Nebraska and Oklahoma or hey…we don’t have any students from Finland) or perhaps they are in search of students with a rare EC activity (we need more people who practice the Brazilian fighting art of Capoeira, and it really helps if that person is also first generation college student and teaches music in a school for the visually impaired). The boxes you need to tick off to get in a school constantly shift in super-selective schools like Harvard, Stanford, Columbia, etc.
It seems the best CS school in the land and an Ivy League college think highly of you. 
IT will sting for a while, but now focus on Carnegie-Mellon and Columbia and make your choice - and don’t look back. Either option is amazing.
If you KNOW you want CS, then go to CMU. It will give you an amazing foundation. If you like the web and front-end design, as bonus unsolicited tip, they also have the best grad program in Human-Computer Interaction in the US, perhaps the world, and if you stick around for a Master’s in that you’ll be in a highly paid creative job as a UX Designer which is a blend of Psychology and Computer Science. Or you can just cash out after your BS in CS and get a job in NYC or the Bay Area for lots of money building whatever cool software you like.
If you’re not sure about CS, and want broader options, Columbia is great. You will come out a well-rounded person. Columbia is no slouch. But, as other folks have said, it’s good, but it’s not stellar in CS at the undergrad level.
You can’t go wrong with either choice. Your life is and future are wondrous. Enjoy it.