I havent field tested this answer but it just popped in my head and i though mabe i should share it. Now i havent done my research and it is entirely possible or even probable that someone out there has said this already and if so I am in no way trying to take it from them but I honestly did just think of this.
What if when you number close in a way that says write such as
you: "You seem like a girl who knows alot about [input topic conversation] here copy down your number so I can get your opinion on it in the future. (This ofcourse is after some amount of comfort and I feel this is the one of teh best ways to number close because it telegraphs very little interest.)
Her: o sorry I have a boyfriend.

you: O i completly understnd my friend has a boyfriend that doesnt let her talk to her friends either. Your such a saint for putting up with that.
Now form this response it puts the social pressure on her to not look like shes being controlled and she may respond with something like

her: O its not that I just dont give out my number to guys who approach me cuz i have a boyfriend

Now you can go two ways with this either turn it to make like shes one of those girls who doenst have any guy friends and neg he liek

You: wow i didnt take you as that girl who doesnt have any male friends you seemed so well rounded not one sided liek that

which which is in other words playing dum to why she wouldnt want a new friend in her life cuz all you truly wnated was friendship and insight or you can say go more direct and say

You: O you thougth I was coming on to you (smile and slight chuckle) no your not really my type but you seemed liek you really knew alot about [insert topic] and i figured you could give me some insight

Using these seems (in my head anyway) like it could really increase your chance of a both a number close and an excuse to text or call without telegraphing any interest because you already have a platform but I haven't field tested so feel free to field test then get back to me about how it works
P.S. i am in no way condoning stealing a man gf i think thats pretty terrible actually but there are three reasons why i still posted this 1. she may just be saying that 2. you can keep her around as an option until the relationship is over.(since most come and go like flys anywya) 3. just being in her social network now (espeially if shes a 9 or a 10) will help you meet good looking women

_________________
A woman's whole life is a history of the affections. ~Washington Irving

This way you will put yourself in the LJBF zone. In the end of the sarge, like the close, you should show interest... It is possible to be too hard to get.

This is tru but at that point where youve already tried a number close and youve basicly been shut out with the i have a boyfriend answer wouldnt it be better to make her beleive you really need her for something so you can number close and fix it later though i do see wat your saying but i dont see a better alternative around that response other than finding out if she has or is pretending to have a boyfriend before hand .Like i said i didnt field test. Any insight into alternatives in the situation? Otherwise i could go out and keep trying until i get that answer then see how it goes. Also what if you were to tlegraph interest during the conversation then stop then pull that so she feels the push and pull factor. What i was gettting at with this response was less making her feel that your actually her friend and more just not feeling as if your hitting on her for example in a situaion where time is greatly a factor and you need a quick close beofore you can sufficiently enough comfort for her to say yes to a number close. IF your fun and energetic enough i feel like she would be less likely to flake and a second meeting on your terms may arise.

_________________
A woman's whole life is a history of the affections. ~Washington Irving

In my opinion, the set is dead anyway... Go for another.

If she says she has a boyfriend i'd probably say something like

"Well that doesnt mean we cant see eachother again"

Now if she really does have a boyfriend that'll probably land you in the good friend category the next time you meet up.

But if shes just using that as a line to protect herself then the next time you meet her she might say "oh we're sorta in the middle of breaking up" or something. Then take it from there.

It normally means that your game failed. Begging for a reason to see her again doesnt help your chances.

Theres loads of easier ways to counter when a girl says that.

My favorite is:

"Yeah me too, maybe they can hang out when we get together"

*Credit David D (i think)*

Your first was quite good, the others will lead only into LJBF territory, and unless you want to just build your social circle why bother.
The whole "Me too, they should hang together", is the only one that ive ever had to use, and both times it worked great.

I have had this reply just 20 minutes ago lool
but anyway I think what our fellow brother said about the set has lost I would say thats true.

If you want them for social proof you can plow forward and get them out as social friends.

Best I would say is move forward dont try to figure out where you went wrong just keep meeting new girls and automatically you will find the solution.

Your brother in arms ,
AVK

I forgot to mention ,

the girl told me to give me phone number out , knowin that the set has failed once she mentioned these words I gave her my email address on facebook , and NOT my phone number.

This is a push move towards her which is good in this situation.

Your brother in arms ,
AVK