While I respectfully disagree with Illusions on many points, I do agree on one. We can chose to spend our money elsewhere if our concerns are not addressed to our satisfaction. So, let's do so.
CUSTOMERS: Many of Renderosity's major competitors have satisfaction-guaranteed refund policies, no dancing about who's fault and responsibility an issue is. To the best of my knowledge (i.e. when I last looked), Poser Pros and 3D Commune are both among these and often carry items from the same artists. There are others as well, I'm sure; these are just the two that pop to mind.
VENDORS: If you are exclusive to Renderosity, please consider changing your status to non-exclusive and selling elsewhere. When I looked into it (about a year ago, I guess) 3D Commune gave a better split WITHOUT requiring you to be exclusive.