I want to treat my acne, But I have no access to treatments... Options

[synechdoche]

Well, I have moderate acne on my face, back and chest, and I went to the dermatologist for it. She gave me a prescription, which worked for awhile, but then all of a sudden the zits attacked my face again. I asked my mom to take me back, but she told me "We'll go soon... it's just that we have bills to pay..."
My parents aren't willing to go through trillions of different products to see which ones work (I think that they don't think acne's that big of a deal, and with my stubborn skin, I'll probably be going through that many products), and I have no way of getting to a store to buy stuff (no allowance, no job, and I'm too young to drive). I want to treat my acne NOW; I don't want to wait till the next dermatologist appointment (which will probably be in the next year if I'm lucky).

So, I guess what I'm saying is, how can I convince my parents that I want to try to treat this NOW (without nagging them to death/being annoying)?

I think I made sense. I hope I did. :P

Thanks!