Funny thing: STL doesn’t support units at all… and if you export th standard cube in meter Cura scales it by 10000… and it measures 200mm on each side… as it should be… so i wonder why the printing company complains… did they deselected the Cura setting: Scale extremely small models ?? (which doesn’t make sense since STL doesn’t support… STL format )
If i add UNIT=m Cura (4.7.0) also scales… 
how could anyone use 3D printers then ???