I don't think she gave you her number to get rid of you, though women do that. Women also give out their number if they're bored and lonely and figure you'll take them out, and if nothing better comes along, then they may go out with you. Maybe something better came along.
You have to ask yourself:
Did she give you her number without hesitation?
When you asked, did she counter by asking for yours first?
Did she offer you her work number instead?
Did she ask you why you wanted her number?
Any of that signals that she's not really interested. An interested girl immediately spells out her digits for you and will write it on your hand if you don't have any paper handy to make sure you have it.
But this is what I think happened:
1. When she was asking you "lots and lots of questions", she was actually searching for flags. Somewhere in the process she gave you her digits, but that may have been before you said something that turned her off by way of your answers or conversation with her. The lesson there is: DON'T ANSWER their questions. DON'T be an open book. If you blink the wrong way, they'll next you. Deflect with humor and kid them around. Gives them some things to discover about you, or you could say, gives them more reason to go out with you.
2. Expecting a new woman to return your call almost guarantees failure. Some may, but it's not typical, even if they ARE interested. Some woman are simply brought up that "a girl doesn't call the guy". Later after you've dated them some, they will, but not always when you first meet. So, basically, what you did was put all the control into her hands by expecting her to return your call while you waited.
3. Persistence doesn't pay off any more then persistently kicking a dead horse gets it to move. Their disinterest isn't reversed because you call more frequently. Imagine an annoying static cell phone call: it doesn't get better just because you talk louder.
4. Writing her back in the tone that you did only reinforced that she made the right choice in not getting involved with you. And she sees through the whole attitude of "I don't want to ever talk to you again", because if someone really didn't want to ever speak to her again, he wouldn't be emailing her.
If you still don't get it, you have to re frame how you look at things. Otherwise, this will happen again and you'll only increase your frustration.
Next time around, don't get into answering their questions unless you answer C+F, get the number and get out. When you call for a date, don't leave messages and don't expect return calls. If she's not in, call again a few days later at a different time. If you leave a VM, just say, word for word: "Hey, it's Trent! Sorry I didn't catch you by your phone. Talk another time, bye." To me, this is the perfect message. If you need to know why, PM me.