this seems strange for several reasons. The first being these engines are not usually too fussy about the kind of oil they use. It has 900km so wouldn't it still be under warranty? A very simple way to check the adjustment is to adjust it fully closed i.e. adjust the cable so it is very slack and then go for a ride.

If for some reason it does need new clutch plates (btw there are six or seven) they are not so expensive and the labour should be no more than one hour.