Buy another oz from him but find a way to short him the price of an 1/8 (or a 1/4 if you figure he'll do it again) Like cut the corners off of some $20's and put them on $1's or print a couple of $20's on the computer and hide them in the middle of the stack. Then when he calls you about it...."Fuck off, if ya don't like it, don't sell"