I'm an intern in the States.
I'm a grad school in South Korea. I had a chance to work in the State and now I'm here.
The problem is I work five days a week.
But other interns from other universities work three days.
So I was curious about if I can reschedule my workdays or not.
I sent email to my boss about my workday. She replied to me that 5 days work is my grad school's plan which I've never heard about. And she said she could change to 4 days.
Yes, it was perfect until I could say thank you. However, my boss sent my email to HER BOSS. (I think it's the company's policy. I can't argue about that.)
Her boss sent me an email that her boss can't understand me because they required me 4 days but I've never heard about it. And she asked me to see her at 1pm tomorrow.

What do I have to say to her and what should I do tomorrow. I'm a little bit nervous and annoyed.

Can anybody give me advice? I'm in emergency right now.