Hey Frank,
My 2¢ is that you may have been able to cut out some of those women earlier on in the process, and not make the next call.
we both agreed based on our last communication that we would try to get together for a third date before she leaves.
There is no "try". You make a date on the call: a definite day and time. Then you wait for her answer. If it's anything other than yes or a counter-offer, you don't proceed.
Got a number from a gal at a party, when I asked for her number, she seemed surprised and scrambled for a piece of paper to give it to me. That seemed to me as if she was eager to give me her number. When I called her, I asked her out for a date a week and a half away. She tells me that it's a busy time of year at work, and that every day up until then is not available, but that the day I mentioned "has potential to work out". You have to understand what they're saying. She's saying that she already knows that every day for the next nine days are impossible to have any time for a cup of coffee, but that the very day I happen to have in mind, she knows ten days ahead of time, that it has the potential to have one hour to grab a cup of coffee sometime in the evening, yet she didn't agree to the date. Wow. You know what that means? That means that's is one amazing clairvoyant ability she has, and that she's not interested.
whose number I'd been trying to get for almost a year and a half, but she kept playing hard to get. ... I called her once and she knew that I had planned to take her on a date that weekend. I left her a message and my call back number and she never called me back.
Here I think the problem was you had been trying to get her number for a year and a half, but she was, in your opinion, "playing hard to get". My interpretation is that if you ask a woman for her number and she doesn't give it to you, she's "not interested". Especially after a year and a half of trying to obtain that number. She may have given you the number just to have you stop hitting on her.
I also wouldn't have left a message announcing my intentions to take her out that weekend. I think it says two things when you call up a woman during the week and ask her out for that weekend. 1. it says to her that you have no other options for that weekend Mr. Lonely Guy, and 2. It says that you don't think she has anything going on for herself either.
gave me her work phone number
And you seem to know what that means.
When I tried to set up a date, she was polite enough to call me on the same day to tell me why she couldn't make it and now we have a date set up for this weekend.
That doesn't bode well for this weekend.
The How to Succeed with Women book would always suggest to make up to two calls before giving up (leaving a voice-mail of an arranged date/meeting) both times before trying with a blocked number... Obviously on the second message you would give a call back ultimatum, where if it's not followed, then it's made clear you wont be calling back again in a very long time.
As if she cares. I don't know about you, but when I've received voice mail from gals delivering ultimatums, I laugh.
Also, ultimatums don't work on adults. Just in principle, an adult will not accept to be forced to do anything when an ultimatum is delivered. Especially someone who isn't interested in the first place. If anything, leaving a message saying anything like, "And if you don't call back, I will not be calling you again" would make you sound like an uptight control freak.
The "Be the bad boy that women love" sequel would suggest to call a woman up on her bad behaviour by deliberately being a bit confrontational, so again, rather than moving on, you call her up on her behaviour in an assertive tone rather than just nexting her.
Setting boundaries by *calmly* telling someone what you will not accept works in a relationship, but not being in a relationship, contacting someone who's probably not interested and getting "confrontational" with them yields this: she'll apologize, maybe you give you a plausible excuse why she hasn't called back, and that's so that you don't think ill of her, because women don't like to be thought of badly, even when they're guilty as sin, and to get you to back down, so that you don't become a nut case on her.
Then she'll go ahead and make the date but stand you up because she'll think "See? He has control and anger issues" and she'll be convinced she was right all along in not getting back to you.
The way to handle someone who doesn't return your phone calls, with whom you're not in a relationship with, is to not contact them. They've already decided not to contact you.