Was the valet key stolen when the car was parked where you frequently park it? If not, the thief might not find your car again.
You might be able to have the all the keys "deleted" from the vehicle ECU memory and then have the keys you still have programmed back in. The thief would still be able to unlock and gain access to your car but the stolen valet key could not be used to start the engine.
If that is not good enough, yes, you can have the service center replace and program new keys but there will be significant expense to change the door and trunk locks and the ignition switch. Insurance may cover much or all of the cost if you have it.