Would you show up for the job or just leave for vacation?

Well, this weekend I had planned to go to Baltimore to visit my family. I put my two weeks in at work (I set the date as Friday and expected it to be until Friday) and was planning on leaving. Well here I am, yes, I've known for a week that I was working this shift, but I thought I'd be able to call around and find someone. Well... BIG MISTAKE. I've called almost 10 stores to try to find a replacement for me, but they've either completely said "NO" or no one's gotten back to me or they said they'd "try". Now I'm sitting here wondering what the hell I'm supposed to do. I'm leaving the job anyways, but at the same time, if I ever need a recommendation, I can't go to them if I decide not to show up... not only that, but I promised my manager that I would show up for my shifts. And now I'm stuck. I really want to go out and have fun with my family and see them and go to Washington DC, but at the same time, I want to keep up a good relationship with my boss. She also signed me up as a student, so if I ever was in a pinch for money and needed to come back, I can always go back to them. It's just really frustrating when I've called over 10 stores, 20 employees and not a single one is willing to work. So what would you do, call off or suck it up and work the shift and find something else fun to do?