Why can't I go on dates with girls?

I don't know what the problem is, but this has happened four times in a row with four different women. I find a girl that I find rather attracted to. We get to know each other a little bit. She gives me her phone number. I ask her out on a date. She thinks that would be a good idea and agrees to go. Now here is the problem: Just a few days or a few hours before our scheduled date, she calls me up and tells me that she can't go. I have heard such lame excuses such as "Sorry, I have to work," or "My sister got me sick," or even "I have to build a shelter for my horse because we believe it is carrying a foal". No kidding here. Of course they aren't able to reschedule for another time, and then they end all contact with me. I'm noticing this pattern, and I find rather annoying. How can I put a stop to this and actually go on a date for once?