Try this advice on for size: write a letter to the school board and the superintendent of the district informing them of the slander that their principal is engaging in. It would be better yet if you had a lawyer friend who would do the letter for you...inform the board and the superintendent that if the slander continues you will be forced to pursue legal action against the principal involved AND the district employing him...that will get their attention and he will be told to knock it off.
Or you could just keep ignoring him and hope he goes away...
