Help get a gaming pc!

You might be thinking 'Oh why don't this guy just work for their stuff like everyone else?' And you're absolutely right and that's what i did. I'm a 15 year old boy and I worked as advertisement deliverer for 5 months to save up for my long wanted PC. When i eventually got the money my parents said they can't do it even though it's my money? I'm currently playing on and have been playing on a crappy old Dell PC that i've been using for years now. I've been planning to get this pc for over a year now and wanted it for Christmas and thought it would be my best Christmas, but little did i know that was not the case. So if you are feeling generous I would very much appreciate any money you give me. Thank you!