Call from garage fitting new cambelt kit?? PROBLEM?

[BigmanDAN]

Hi everyone new to this site, took my passat 1.9 tdi 130 sport into a local garage to get a new cambelt kit & waterpump & both aux belts fitted today, within a couple of hours he phoned me up saying, that there was no camshaft vibration damper even fitted to the vehicle & metal was rubbing on metal?? charged me £75 for the part & no extra labour which was good of him, but what i want to find out is, how much damage could this of caused to the engine itself with this vibration damper not present?, and how could it of not been fitted? previous cambelt replacement 14k ago? thanks Dan