Happened to me five days after I bought my IS back in October.
They made a complete hash of the rear one, with scratches around the key hole, breaking the badge and leaving it in the end. The front badge was gone completely, but they also broke the bit it attaches to, so I had to get a new grille in the end (90 quid incl. labour).
Steve
PS - first post here, just decided to join after lurking for a bit