I called the phone number and spoke to a delightfully friendly person named Adam. I told him my situation, and he said that he can just take my info via phone and will submit my rental request for me. So we went through the process: I gave him my name and all my contact info (including my email, karenng@alum.MIT.edu), gave him my height, weight, and credit card number. Then he told me I'm all set and that I can pick up the gown any time before graduation.
Then I said, "Just to confirm, I can pick it up in the Kendall Coop, right? Not the MIT Student Center Coop?"
And then Adam paused.
And said, "Oh. This is actually the Harvard Coop. I guess I forgot to ask you the most important question, which school you're graduating from. And you even said your email was alum.MIT.edu, but we have a lot of Harvard students with MIT email addresses."
Me: "...Oh." I'm such an idiot.
Adam: "Welllll... Let me ask my supervisor and see what the correct protocol is for transferring this order to MIT."
Me (so embarrassed): "No no no, it's okay, just cancel the order, and I'll call the MIT Coop. I'm really sorry..."
I hung up the phone, and turned to my boss, who was sitting next to me (we work in a conference room, with 3 other people, who weren't there yet) and told him, "I just ordered my graduation gown from the wrong school."
I don't deserve to graduate. :(