My Fissler Pressure Cooker is Malfunctioning

My pressure cooker is always letting steam out, which lets water leak out and stops the pressure from building up. So, my food doesn't cook right, and when the water evaporates, it burns the food. Even though I try to close the lid properly, the problem still happens. I have tried to open and close the lid many times, but nothing has worked. The lid closes like a normal pot lid, and it keeps opening on its own. So, I'm asking that the product be replaced with a new one or that I be given my money back. I would also like for customer service to answer my questions and help me figure out how to fix this problem.