Zanussi 1400 6kg washing machine door won't open?

Hi, my Zanussi 1400 6kg washing machine door won't open after it's finished a cycle. It looks like there is still water in the drum therefore I'm wondering if it's a draining problem? I have tried turning it off on at the machine and the plug however when it turns back on the door is still locked. I have tried doing another cycle but it still won't open. Please help. Thank you