zanussi zbp 1165 oven door locked shut help?

Hi

my zanussi oven door has been locked for over 2 weeks and will not open. The cleaning cycle was not active or broken at the time. Main display has no key to say the oven door is locked but it will not open, have tried all i can think of does anyone know what i can do to get it open? oven heats up etc just cannot open the door.
Thanks :)