Help, mk6 not locking/unlocking

[Okedoke]

We have a 02 tourneo, I've tried locking but it won't, the company we Brought it from have said they haven't locked it for a while now as it been in a secure compound so we have tried drivers door nothing, had a locksmith out and he tried syncing a remote, he got it to sync with fob but it just unlocked it's self again ... Managed to lock n/s drivers door with the key... Then wouldn't unlock unless we got in drivers side and pulled handle... Now won't relock lol, it has had new or replacement sliding doors, so I've got to see if contacts are joining correctly..... Other than that I'm stumbled..... Doesnt help im not mechanically minded ... Any help would be greatly appreciated