hi there i am dean i currently work at peugeot and kia as diagnostic/master tech. i would be happy to assist you with your problems
If your locking remote is technically ok you can reset them.
what to do is put the key in the ignition but in the off position.
Hold in the button closest to the key blade and turn the ignition on at the same time
and hold for 10secs
hen remove key from the barrel
and check the lock and unlock
if it still does not work you will be looking at faulty plips
Hope this helps
you could try disconnecting the battery then code them again.
If you are disconnecting the battery open the bonnet and shut all the doors and leave the car alone for 15mins to allow the bsi to shut down properly then disconnect and leave for 15mins and reconnect and code them again. If that doesnt work I would recommend getting the plips tested and a diagnostic check as there could be a fault with the receiver in the car.