Parents

So today, my iPad got taken away because I didn't finish practicing 2 hours of piano before my parents returned from work. Its going to return on July 31st. Now I'm a bit mad about that. But that's not the point.
While I was online chatting with one of my friends, my dad said, "Oh, I guess your device is more important than your father". Now that really ticked me off. I don't know why, But I feel like he's manipulating me sorta? I don't know. He's always used that line whenever I'm on my iPad and claims that he's not as important as that. So then he takes it away. And he could've taken it away for a week, but no, it has to be a month. He says he has to do it so I'll listen to him and not disobey him anymore.
And I've also been finding traces of that in my mom too. She tells me to do things saying its for my own good. They both say that I should listen to them because they are my parents, and I'm the daughter, so I should respect them. My mom also says things like, "Oh, but don't you want to _________?" stuff like that.

Are my parents actually being manipulative, or is it just my own delusions? They've even gotten me a therapist for thinking about all of this.