I thought I saw someone mention @Garry H (Cut Nut) had referenced a D IF with similar issues. Not sure if that was a joke or a rare situation.
Perhaps he can further comment?
ctd.
I suspect that none of the labs offers a formal procedure to contest grades; on the contrary. I do not know to instigate blind re-grading, except by another lab.
Tough, this ,(
Did you manage to take the stone to the appraiser or send to be graded at gia?