Punishment for Scammers?

Where is the backlash from Scamming? If blizzard wants to promote pugging and make the game more accessible to other players why is there no punishment for scamming? I just had a guy steal over 21000 gold from a 25 man group and nothing is going to be done about it. Every single time I have put in a ticket for someone stealing loot or gold I get a message back from Blizzard saying "There's nothing we can do. Please choose who you play with better." There's no way to know if someone is going to take something. So what they really mean is don't run anything outside of your guild. Don't play outside of your guilds raid time. Don't have any fun and quit playing our game. The only time I've ever felt like cancelling my account is when I get Items taken from me that I worked hard to get.

Has anyone gotten different responses from Blizzard for scam tickets?

Why doesn't blizzard implement a player rating system? Or any kind of system to deter scammers. Why not perma ban them? Their measly $15 a month is nothing compared to the 10 million other active accounts. For God's sake do SOMETHING.