How do you get your parents to stop breathing down your neck?

My parents are very strict and tight about money, and although I know that I should start saving now that I have a job, I've had things that I've wanted to pay for and so my money from three days of work is more or less gone - but it's okay, I feel, because I will eventually pay off the "debt" that I should to save money. My mum will not let it go though, and though I've admitted that I've been a little irresponsible, she can't seem to understand that I'm happy to makes these choices whilst I can, because I'm sixteen, only going to live once, and right now would just like to live the best sixteen year old life I can - I'm fed up of them forcing on me what's ahead of me in the future, all these responsibilities.. maybe I would regret not listening to them full stop but it's just so much pressure that I'd rather not deal with right now, because at the moment I have basically all the freedom I could have, and I hate that it feels like they're taking it away from me. I just want them to stop repeating the same argument, let me make my own mistakes and decisions, and if it's not something they'd do then.. well. so what really?