I'm mad at my parents. Help?

My parents stole 10 bucks from me! I know it's not a lot but you haven't heard the reason why I'm so pissed. I love my parents but EVERY SINGLE TIME I make my own money I put it somewhere safe and then lets say a week later it magically disappears. My dad used to take money from me and sometimes my mom did to. Once when I was little my grandma gave me 180$ for Christmas, and then a month later I thought of something I wanted to buy that was around that amount. Apparently my mother took the money, and to this day I don't know what for. I mean if they needed extra cash for something or needed to use my money for bills they could have asked and I would have lended them money. And they don't even tell me. Now, none of them are fessing up to it but I have a sneaking suspicion my mom took the money because when I told her she was like "Oh I didn't take your money. Why would I do that?" kinda stuff over and over. How do I get them to stop? Thanks.