I know the feeling and I have to agree with Damien's reply. It seems HBs will generally give a number out of obligation or even pity if you request it. An NC means almost nothing and can actually beat down your confidence when you get rejected after the NC. The trick then is if you are only looking to NC, then go NC and be happy with that and don't expect anything more to ever come of it. If you want more, then go interact with her and bring her to the goal instead of ejecting at NC.. set up a date, K-Close, F-Close, whatever you want from the night and maybe number close when you've reached the ultimate goal.
By the way I have not been practicing what I'm preaching. I'm just coming to terms with the situation I'm in which has been similar to yours. My goal at this stage is mostly just to NC to show myself I can NC. Also I have been dating one for the past year+ so I can't branch out too far (ending though). Just recently I met one I really wanted to take out but went for the NC and ejected. It turns out she had a BF (I met him last night actually!) and the NC was just obligatory/kind/whatever. Last night I did a NC on one that I really have no further plans with other than being friendly/huggy/use for DHV in future encounters at the clubs. By not following up, I will make myself seem low access and this will intrigue her. On the right kind of night (lonely/slow) she might manage to F-Close me though!
Like Damien said, setting a goal of NC is a cop out of sorts. I think it's fine to have that goal for practice/confidence building. Just stay out of the trap of changing your goal after the NC. It will bring you down every time you get shut out after NC. It sounds like it is time for you to move up to the next level just like I need to!