It is more than likely that it is the door handle or door lock that is the cause of the prob.
To release the door, you are goiung to have to remove the top cover, and force the door open from the inside with a long screwdriver or similar.
You may break the door lock doi g this, so be prepared to fit a new one.
If you manage to get the door open, then you need to sepreate the 2 halfs of the door to gain access to the handle and spring.
If you require further assistance, please e-mail me.
Good luck.