Reporting them might help, but it seems they (spammers) are able to create accounts automatically, seeing as how few posts mosts of those accounts have.
So, the question then becomes "Is there a better platform that everyone here can use to share solutions and ideas?" I don't think Authorize.net monitors their own forums much any more.
If you have a question, try firstname.lastname@example.org. I usually get replies within 24-48 hours.
It is sad to see those forums becoming a wasteland. :-(