We secretly replaced your old worn parts with even older worn parts...
“The main reason … is that many airlines currently using the A380-800 will have a high demand for individual replacement components due to upcoming maintenance intervals,”
:/ it's typically good form to replace those old worn parts with non-worn NEW parts during maintenance, not even older worn parts.
"Hi, we had to replace your tires on your 2010 Ford. However, instead of replacing them with new tires, we opted to replace them with some tires we found on a 1995 model in a scrap yard."