If the warpage is in the plywood substrate, you probably will not be able to adequately repair the counter by simply gluing and clamping it. Most likely, you will just need to replace the entire countertop. How extensive is the damage? Is it just lifting laminate at the front edge of the counter, or is it a big bubble in the field of the laminate? A bit more detail will help us have a better idea how to advise you.