hello, i was just wondering if you could help me, i brought a polo and the locking dont work, i have to lock the doors on the inside when i get out, and then open them by getting in the boot.

just wondering if anyone has any ideas to what it could be? any pics would be a good help to. when i insert the key it is as though there is nothing inside of the lock.
good forum by the way, look forward to the Dub side
thanks chris
EDIT: just thought i would add there is no wirling noise when i lift the pins up and down, so i think a new pump is needed and also am i right in thinking that the pump is in the right of the boot? in the foam?