First, write down all the reasons you feel that you should have more space. List arguments as to why these reasons are valid. An example would be:
1. I'm responsible. I do my chores regularly without you having to remind me, phone whenever I'm going to late, etc.
Then ask your parents for a discussion on the issue. State your case in a calm manner. Remember you are trying to convince them that you are mature enough to have a few less limits put on you.
Ask them why they are reluctant to give you more space. Listen politely and respectfully to EVERYTHING they have to say. Try to counter their objections with facts not promises to change.
If they still object, try to find out what changes you would have to make in order for them to agree. Make written note of them for later use. Ask your parents for a follow-up meeting to determine how you are doing with your changes in your quest for more freedom.