I agree that the dyeing of fish is a disgusting practice.
But nothing can really be done to stop it as long as there is a demand, unfortunately the seller here is right. He knows the industry, he knows there is a demand, and his morals (or lack there of) allow him to sell those tortured fish.
I think it was right of you guys to inform the seller of the situation regarding thsoe particular fish, if he had not known already. And purhaps suggesting that he lable teh fish as dyed would have been nice too. But i dout harassing this individual will do any more than piss him off.
Do u know that this practice of selling dyed fish is annoying to most of the general hobbiests ant there and were all hopeing that these fish will be banned for being sold ASAP.
If i were said seller in question (though id never sell dyed fish), id be quite upset that somone would approach me about my merchandise in such an informal fashion as you have (if that is indeed the message you sent to him.) This is by no means a personal attack or anything; but in teh future it would prove more effective to write a gramatically correct response to a seller's auction. This is what likely provoked his less than friendly response.
BTW, this post in is no way gramatically correct either; i am aware. Were it formal, it would be.