<human>: First off, I'm just going call this friend Carrie throughout this post. I've known her for 13 years and she's been one of my best friends for 9+ years.

So, I'm graduating high school in 3 weeks, and for part of the ceremony, the people organizing it all ask you to sign up in groups of 4 for who you walk onto the stage with and sit down with (it literally will take 1 minute). Carrie and I had discussed this and who we'd be walking with earlier, but never made any promises or official decisions as to who we would for sure be walking with. 

On Monday, 3 of my other best friends - one of which being my all time best friends since we were 3 who doesn't get along with Carrie very well -  (all 17/f) came up to me and asked me if I would be in their group of 4 for the commencement, and I said sure. We signed up. No big deal. I just thought that if Carrie signed up with some of her other friends for right after us she could still sit with me and it would all be good, but apparently not.

Carrie saw the sign up sheet before I had a chance to tell her that I was walking with 3 of my other friends and she has been completely ignoring me in person and through text ever since. I tried speaking to her today, but she just looked at me today and purposely walked into my shoulder and kept walking away, ignoring me. I've tried to explain to her why I chose to be with my other friends, but she just won't even acknowledge me.

My friends and I are a very close bunch who never fight, never have drama, or anything, so I'm super confused as to why she's acting this way, because it's never happened before.

I don't know how to talk to her or maybe make her understand that I didn't do this because I hate her. I'm really upset that she's acting this way and I just don't know what to do. Any advice would be greatly appreciated. If anything is unclear, just ask and I'll try to clarify. Thanks.

Give me a shortened version of the text
<bot>: My friend of over 9 years is completely ignoring my by text and in person because I'm not walking with her on stage for our graduation and I don't know what to do.