Last year my C scope had a handwritten note saying "lenses not perfect". I found small dirt inside the objective lens (impossible to notice while using it). Good deal imo and I still have the warranty if something happens.
Also got precision matched rings with a stripped screw. I called Vortex the same day and I had a prepaid Purolator label 10 mins later. One week later I received brand new rings and some Vortex goodies (baseball cap, stickers and badge).
I suggest to call Vortex if there's an issue. They are good to deal with.