How can I get ungrounded?

Okay so I'm fourteen years old and my mom said that i shouldn't go out and chill with my friends on saturday night. I thought that was crazy but i knew if i asked her she's get into one of her fits and spazz out on me. She overexagetates and gets mad about the smallest things. But, i went out anyways and told her i was going to my dads house. I was just hanging out in the park for a while and then me and my friends were driving around. After, we went to my friends basement and played domino's and cards. He lives 3 blocks away from me. And i live in a very safe neighborhood in NYC (Never sleeps, people are always out, SAFE) and i returned home at 12:30, my usual curfew is like 11:45 so it was no big deal. She got really angry i explained everything to her and she grounded me for the next weekend. I think that sucks because i am getting A's in school and i have 3 after school programs and i work so hard and i cant stand to have my weekend taken away from me. Its to much for me to not have a break from all that school and stuff. I also have the stress of my parents divorce and everything. I dont do anything bad when I'm out and I'm always safe and with a group of people. I really need to get ungrounded... =/