96 C280, Infrared remote and receiver for keyless entry
 

There is a receiver attached to the rear view; it communicates with the key to lock/unlock the doors and trunk. It blinks with a green or red light telling you if it's locking or unlocking.The receiver has stopped working, no blinking lights, and the doors no longer lock or unlock with the key. Tried both transmitter keys that I have, the second set had fresh batteries and neither worked. A reset of the central locking system didn't help either.

Has anyone had this problem or know anything about it?
Where can I find a replacement part?

Any info outside of "Go to the dealer" would be most appreciated.