I'm sure you keep the place very clean, and I'm sure you're good at your job but I have to say, you're making decent money for the position. If I were you, I'd find another kitchen where they're willing to let you work prep or pantry. That way you can move up from there. You've pretty much hit the ceiling as far as pay for your present position.

You're not going to make much cleaning no matter what you're cleaning or where. Your profile says you're a prep cook so I'm confused as to what your position actually is. If you are a prep cook making 12 an hour then you're a well-paid prep cook.