How to re-ask about my blackberry grad present?

So it's now a day and a bit past my grad and a month before grad I asked for a blackberry to be my graduation present. My mom got really upset when I presented this suggestion! I'm more then willing to pay the difference of what my phone costs and pay for the actual blackberry. At grad I was valedictorian and ended up with 6 awards so it's not like I'm not a hard school worker and don't deserve it. I thought all my awards would've shown my mom and dad how much I really worked at school this year, yet here I am still with no grad present at all, more then 24hrs. after my grad. I'm just wondering how can I bring up the conversation of a blackberry without getting my mom really upset My older sister and mom have blackberry's! My dad is useless with technology, lol! So he doesn't have one. Any tips much appreciated!