Not in particular, but I think either "Billing and Accounting" or "Web Hosting Business and Legal Issues" should both be suitable. If fraud has to do with billing, then Billing and Accounting forum would be a good forum to post in.
I think it would help to give host providers a way to post info on "fake" orders they're getting, like IP Address they ordered from and email address they use. I've seen more and more frauds from paypal. Too many "idiots" clicking on the spam email thought from paypal.
Hosts nowadays have to be more cautious, but that in return, causes some delays in processing "real" orders.