what does dill say that causes scout to accuse him of lying?

From the text:

"Well how’d you feel if you’d been shut up for a hundred years with nothin‘ but cats to eat? I bet he’s got a beard down to here-" "Like your daddy’s?"

"He ain’t got a beard, he-" Dill stopped, as if trying to remember.

"Uh huh, caughtcha," I said. "You said ‘fore you were off the train good your daddy had a black beard-"

"If it’s all the same to you he shaved it off last summer! Yeah, an‘ I’ve got the letter to prove it—he sent me two dollars, too!"

"Keep on—I reckon he even sent you a mounted police uniform! That’n never showed up, did it? You just keep on tellin‘ ’em, son-"