K.C.
When I was 11 years old, my parents took away my allowance and I had to work for extra cash. They gave me lunch money and bought me school clothes once a year, christmas gifts and a birthday gift: nothing more.
This worked very well. I had to have all my chores done by Sunday, or no money. If I didn't do my chores, I had no cash for makeup, rollerskating, cassettes (LOL), etc.
I am now 34 years old, and the most financially responsible person I know (besides my mom). I have no debt and own two homes. I believe it was the work ethic my parents instilled in me that made me this way.
They may hate you at first, but in the long run, they'll appreciate it.
Good luck.