Miss a chance at last

After asking some advice frm my senior,i made a decision to go for usm.Unfortunately,i overlooked the time for me to answer usm admission offer.At last, i miss it forever.I am trying to call usm tomoro.Hope they will consider again for my mistakes. I know it is impossible for me to have my second chance. Hwever, after i made my decision clear,i won't miss it again ....