Starting with poor communication from the person whose shift I offered to take

Ugh... This sucks ass. I missed a catering shift, and I don't feel like it was really my fault. I agreed to take someone's Wednesday shift, and then he e-mailed me saying it was a Tuesday shift and could I still work, and to e-mail him back if I couldn't. So I e-mailed him asking him to remind me what time the shift was, since I had accidentally deleted the e-mail. (This part was my fault.) So it's 2 am the day of "my" shift, and he hasn't e-mailed me back, so I e-mail my manager and explain the details and ask her to e-mail me. So then I leave my computer and Outlook on, as well as my speakers, so I'd be able to hear when the e-mail comes in. In addition, since I thought the shift was at 10 am, I made sure to check my e-mail myself at 8:30, and there's nothing, so I go back to bed with my speakers still on wondering if I will get e-mailed. I then get up at 12:30 with an e-mail that arrived at 8:45, and a message from Stephanie which I haven't listened to, and a message from my dad saying that he got a call from Stephanie and to tell people my new number and not to call the old one. (Seriously, people, you have my number, and you got my voice mail - why do you feel the need to try my old number?)
Now, to specifically mention something I could have done better, I realize now I should have actually called her when I hadn't gotten an e-mail by 8:30, especially since that was close to the brink of when I'd have to leave for what I thought might have been a 10 am shift. I think I also poorly associated not getting a message from her with situations in which I offer to take a free shift and her not e-mailing me means someone else got the shift. Actually, the other big thing I could have done was be more careful about not deleting the original e-mail. I'm usually not so stupid. ><;
After this bit, I'm very glad I have perfect attendance at RMCF so far (although none of my shifts have started before 1:30 so far, so I can't get too proud).