<human>: Could you distill the essence of the text into 1-3 sentences?

Hi so I just went back to school today as I am sure plenty of people did. At my school we have this dance after Easter for the year 11's. 

Before we went on school break, I asked my best friend Sami if he would go with me because I had just broken up with my boyfriend and he accepted. 

Over the school holidays I got back together with my boyfriend and he asked me if I would go to the dance with him and I said yes. I forgot to cancel with Sami. 

Sami came up to me at school and he said what time do you want to meet tomorrow and I told him we are not going anywhere and he flipped out on me

( he told me off because he spent $200 dollars on a formal suite that met the requirements, he told me he could have gone with a girl he like Chloe when she asked him, and he told me off for not telling him)

He walked off and said  " you know what fuck it, what ever I am going to see if I can get a shift at the surf shack tomorrow night" The dance is tomorrow night 

I just feel really bad that I wasted his money and time, what can I do to fix it
<bot>: I ask my best friend to go with me to the dance, I ditched him when I got back together with my boyfriend and I did not tell him until today one day before the dance.