You can buy a stem with more angle to it that will give you a little more height, but unless you have steerer tube above the stem at it's current position, you can't do much else easily.

Your desire to have more height makes me think you need a different bike. Can you return this one? Might just be you need a bigger size or different model that's a different geometry. Don't buy a bike style, just to have that style. Make sure it's got the geometry you want.