You can change the size of the logo in Height field, but your logo must be bigger. If your logo has 150px of height, you can't set a 300px. Your logo must be a 300px to apply this value.
Of course, it works backwards, if your logo have 300px, you can set a 150px of height, so your logo will be smaller.
Comments
BeTheme is resizing logo size automatically, to be 100% responsive.
All options of logo size are in Theme Options > Global > Logo
If your logo has 150px of height, you can't set a 300px. Your logo must be a 300px to apply this value.