Missing spare parts to radiator.

I personally handed my radiator to Klerksdorp branch for repairs. It was fitted with a manufacturer drainplug. When installing it I found the drainplug (an expensive and sc**** spare part on an excavator) to be replaced by a standard drain plug. The employees at this branch refused to admit losing my part and management decided to take their word above mine. Other than that, the leak was repaired.