There is a non-zero net force in this instance because the parcel's direction is changing (a form of acceleration). In this case, the magnetude of the pressure gradient force is less than the magnitude of the coriolis deflection because the parcel's path bends to the right (not straight, as it would be if the two forces were in balance). The net force is inward, and is called the centripetal force. The magnitude is $\displaystyle{\frac{v^2}{r_0}}$ where $v$ is the parcel's speed and $r_0$ is the radius of curvature of the parcel's path.