Door lock won't lock/unlock

Hi there people! I have an 87 cabby, my door lock has been dodgy for a while, gotta be really careful with it otherwise it wouldn't unlock, my misses went into my car yesterday to nick my aux cable and she managed to unlock and lock it again but when I went to get into it this morning fr work, the barrel just spun all the way around without unlocking it, I tried for 10 mins and still couldn't get in so I had to open the boot and climb through and unlock using the pin! Can anybody help me? My passenger door has never worked on the key, the key is right but it just doesn't work, it's the same as what the drivers door has just done to me

Thanks for any help

take the handles off and have a look. screw in end of door, and another under the door handle trim

Is there armour door plates fitted to the handles ? These can make the door handle sit further away from the lock workings as inside there is a fork which lifts or lowers the lock and if the handle is further away or the fork is bent it wont be able to lock or unlock the door.

I'm not sure how to tell if I have armoured door plates or not, I have had the handle off and fixed the problem, I think I do have the armoured ones, they are pretty heavy metal!?

Anyway! The problem, the screw in the end of the flick bit at the back of the lock had come loose so when turning the key it wasn't turning the selector thing lol! Sorted and it's as smooth as it's ever been! Was abit of a fiddle to get everything back in properly, not to mention the door lock pin lol

Link to armour door plates.

http://www.candrenterprises.co.uk/shop/armour-door-plates-vw-door-protectors-vw-1974-1984.html