Tax Withheld $300 from $1000 scholarship

So I got a $1000 scholarship from my University for doing some artwork as part of the Latin American studies department competition. I was told the money was going to tuition, so when they sent me a W-8BEN, I filled it out without the Tax Treaty section. I am a Mexican immigrant on an F-1 visa and should not have 30% tax withheld from the scholarship, but they still only gave me $700 out of the $1000.

Is there any appeal I can make? I figured the Tax Treaty section is only applicable if I have a RFC number, but I don’t since I moved to the states when I was 11.