I have an AEG Lavamat 16820 washer dryer and the

The lock is rubbish on this machine but as a temporary measure you can feed a string down behind the door lock from the top and out the bottom. Then yank it to the left to open the lock. It will take a few tries but you get the hang of it!
We got sick of this so ordered a new lock off the net. I basically had to break the old mechanism to fit the new one because the door layers were so strongly glued together. Now fitted, the lock works perfectly but the machine thinks the door's open the whole time! Next step is either new door or new machine. Great.