[toni-a]

«I'm a bit surprised that they even tried rather than simply replacing a bigger component. Or maybe they did, and the replacement part was a dud.»

They did replace a bigger component — actually two. The invoce is really detailed and they included part replacement serial numbers. Googling I found they are the  “3rd and 4th group assy” — the word “assy“ is pretty new to me, but if I'm not wrong is more or less a lens group, right? In the invoice they are labeled “STEADY SHO(T)” and “3RD IRIS” and the labour description includes "replacement of internal lens groups” (translated).

When they looked at the test I sent them they were puzzled and asked whether I suspected a bump during delivery. The packaging indeed was not showing any sign of that.


   Ah yes the old "damage during transit" excuse .
After clarifying that the packaging bore zero signs of any impacts,  now's the time to insist on a replacement lens .... they really don't allow the time for a full optical test of yours .... no doubt there is a stack awaiting repair already .....  
 Insist simply and kindly on another lens before their inevitable factory response of: "no fault found" ... "or lens within specifications" brings an end to any further redress ..... 

very well said