If they somehow messed up the fuel filler door locking acutator (not near where they were working), your central locking won't work. Not sure if there is a fuse for that; check the glove box card and you can also check inside the right rear of the trunk where the cutout is. There are a bunch of fuses and relays back there. If I had to guess where a fuse would go for a fuel filler door actuator, it would be there, just on the other side of the fuel filler door.
Try the second key, make sure it is not a key that simply somehow got "unprogrammed". They can reprogram it for no charge or you can do a search here. But you need two keys to reprogram.
Regards,
Jerry