Please pursue the refund / refunds for all paid content. I've done so multiple times (on OF not Fansly) mostly out of principle. Only the platforms can provide the pressure to reduce scumbag behavior, and they'll only listen to $.
I think the ethical line is at scammy structuring. No previews, lying about what the content is, structuring PPVs, &c. I don't blame big names for having an agency, and some agencies are decent enough to the consumer. Even reposting old content is ok if it's marked as such (old content marked as new, scammy of course)