Where can I find a better part-time paying job than working at Target?

I'm currently a 17 year-old living in New Jersey who is in some sort of a dilemma. I'm currently working at Target @ $7.25 an hour, working about 10-15 hours a week (with 20 hours a week max availability). I have a pretty open and flexible availability, but I'm not being scheduled enough. My dad has also worked at the same location, and whenever him and I complained that we needed more hours, they gave us less instead. My problem is I need a job that will give me more hours or a higher pay, because I want to save up for a new car and be able to pay for gas, insurance, etc. My parents won't help me at all because they have their own financial issues, which puts even more pressure on me. I really need the money for a car so I can get out whenever I want and not rely on anyone. I'm not even looking for something brand new. I want something used. I can't even get a co-signer either. Someone please suggest where I can find a better job!!!