I suspect the problem may be with the formulation or condition of the pizza dough you are using. If you can tell me what the ingredients are, I might be able to offer more constructive advice. However, one way to get increased crispiness in general is to let the dough rise in your pan for about a half hour or so before putting on the sauce, cheese and toppings, and after dressing the pizza bake it at about 450-475 degrees F until the top crust is browned and the cheese is melted and just starting to turn light brown. Part way through the baking, you can also slide the pizza off of the pan onto one of the oven racks and let it finish baking there. You should watch the bottom of the pizza so that it doesn't burn. Each premade dough and each oven is different, so you may have to do some experimenting with the way the pizza bakes in your oven.