Sounds to me like the whole interaction only lasted minutes, in that time you managed to bring up some attraction perhaps, by negging, now there's a fine line there, don't forget. Negging this early can come off as try hard, but I use a lot of negs in my game and it took me a while to perfect the timing, so I stand by it.
You established attraction, then you bailed on an isolation attempt, where you could have kinoed, built real attraction and even comfort, even skipped comfort and gone straight into sexual escalation(what the dancefloor is all about!)
At the end, you ask for her number in a very confrontational way, you are telling her you want her number in an "romantic" fashion. This puts pressure on her, and she is more likely not to give it out.
My advice is to pump up your attraction and sexual escalation, and using casual approaches to getting numbers. Your whole approach seemed textbooked to raise her alarms
Hope it helps, bro.