Did the same to me, they are a week point of the car.
Just break the rest of the plastic with pliers that is part of the handle unit, you'll eventually be able to find the lever that attached to the handle which if you can manage to pull on, will open. The rest of the handle can be removed once the glove box is open but don't through it away before you get a new one as you will need to extract the old lock barrel to fit in your new unit.
Jamie