Parents won't let me buy a hair straightener, wtf?

My parents are the typical asians, as you see. So I got some money from chinese new years (<3, $60) and I really need a hair straightener. My hair is thick, and straight, but not exactly. What really gets me about my hair is that when I take a shower then go to sleep with my hair wet, my hair will be all wavy on one side, and straight on the other. and sometimes, my hair gets poofy, which is the reason why i tie up my hair a lot. It pisses me off that I can't even buy a hair straightener to use when I need it. So this is how I asked my dad about a hair straightener:
Me: Dad, can you take me to target?
dad: sure, what do you need?
me: I need to buy a hair straightener..
dad: oh, the nevermind. you should be proud that you have thick hair (blah blah blah bull **** bull **** bullshit)
I DON'T EVEN WEAR MAKE UP. i'm 14 btw.

How can I convince my dad.. or mom = =;
It honestly pisses me off that I can't even buy beauty products, let alone facial products
my mom thinks that i don't drink enough water when ever i tell her that something hurts, such as chapped lips, or a bruise (wth?) or a sore throat, or when my skin is dry

It took me 2 years to convince my dad to get me contacts.