Berling van 2010 rear door central lock

[seymour1]

Hi everyone.
  I'm having problems with my rear door cental locking. A few months ago I had my van broken into, they used a screwdriver below the rear door handle and punched through the door and mechanism that locks the van. I managed to get it all back together but the rear door would not open once shut and opening the van from the front would not open the rear door either. So today i fitted a lock i bought off of ebay. 
The problem now is; when i lock the doors using the front door I hear the doors all lock but then they open up again! I can go to the back door and lock it on its own.Then go to the front and lock thoes two together. But all 3 are not in sync. I did notice the led light on the dashboard lock button was flashing once everything was locked...not sure if it used to do that.
 If anyone can help I would be greatful.
 i was told that the way they broke into my van was common and easy. I have noticed now on a few vans that they have had a bit of plate fitted around the handle, my next job. May be an idea for other berlingo van owners.
  Thanks in advance s

[Tomcat3]

Hi Seymour welcome to the forum, it sounds like the central looking motor to the back door is not lined up properly so it is not able to lock and will automatically unlock. With a bit of luck the actuator or the lock just needs adjusting or rods/ linkage could be slightly bent by the scum that broke in.