Let me amend my stance then: No one except the FCC should be in a position to decide whether or not a call is "fraudulent." Not even operator supervisors.
What amount makes a call "non-consumer?" Is up to the operator's supervisor to decide that "100 of something is too much, but 75 is fine?" I wouldn't want someone to be able to make that judgement for my calls, or to break transparency to tell a business that "I may fit a pattern of fraud" that any business would have to watch out for themselves if the call NEVER went through relay. Caveat emptor to the business.
Deaf people do order silly amounts of stuff that people wouldn't think they'd do otherwise.
MCI says they can block them, but choose not to? Bull. They can't BLOCK THEM ALL. It's impossible because of the nature of the internet. Sounds like someone who told you doesn't know how the internet works, and is just parroting what they were told by someone higher up. The knowledge that I have and the information given to me by Sprint Relay says it's impossible.
Until the FCC says, "Get rid of internet relay" the fraud calls will continue to go through, plain and simple.