Recalcitrant Central Locking

[Howelligan]

I picked up a 2004 Toyota Avalon yesterday. It needs some TLC cosmetically, but seems otherwise fine mechanically.
However it has a major issue with its Central Locking. 
The story goes like this- Apparently it was fine until yesterday morning, when the previous owner discovered it had a flat battery. He says he disconnected the battery to put it on charge. When he reconnected it in the afternoon the Central Locking locked the car & has since steadfastly refused to unlock &/or remain unlocked via use of either the remote key fob, the key itself, or the Central Locking Switch on the driver's door.
You can hear the actuators functioning when the locking is 'switched', & if the key is in the ignition with it 'turned on' any door lock which is 'unlocked' manually will remain 'unlocked' until the ignition is 'turned off', at which time they all lock immediately.
I've tried a number of 'sequences' for 'resetting' the Central Locking, which I've found via Google, disconnecting & reconnecting the battery, etc., but to no avail.
I thought perhaps a Toyota Dealership might be willing/able to assist in 'resetting' the Central Locking, so I called Midland Toyota 'Service' Department. Unfortunately the term 'Service' is somewhat misleading, as their solution is to book it in after Christmas & they can look at it then. They don't seem to understand that parking the car with the window down, so I can get back in it, isn't terribly secure, & won't go so well in the rain either. If there's a Toyota Service Centre in Perth Metro Area that actually does 'Service', or anyone else who knows how to get it sorted, any help would be greatly appreciated. Thanks in advance.

Edited December 19, 2016 by Howelligan
Typo.

[trentmeyer23]

I don't think you understand just how busy mechanics get at this time of year. It may not be as simple as you think and may require a large amount of diagnosis.

[campbeam]

Central locking in my Aurion went haywire one day a few months ago, lock then a few minutes later relock again.

I unlocked the vehicle, opened the drivers door, key in ignition and lowered window. Then sat in driver,s seat and closed door.

I then used the central locking switch on the door. Did this a few times with the key in the ignition and out of the ignition. Do not remember if I also started the engine while pressing on the door switch. Eventually the doors locked and unlocked using the door switch. Then exited vehicle and locked and unlocked doors with the remote.

Perhaps just blind luck or a bit of perserverance. No problems since then with the central locking.