Dying my hair something went wrong. How can I fix it?

Well I used box dye to dye my hair...I've box it plenty times b4. It was dark ash blonde...only the top come out blonde which isn't even the box color...and the bottom stayed brown..I hve skool tomorrow plz hlp wat can I do..dnt b rude..if u hve nothing nice to say dnt comment. Thnksz