Really getting tired of SaaS-makers relying on serveless, not monitoring or controlling ANYTHING, and then trying to put the service they use on blast publicly to try to negotiate themselves a special deal.
It's not even SaaS-makers sometimes. Last time I remember it was a casino trying to get sentiment and attention so that they could continue abusing Cloudflare for $250/mo [0]. This honestly needs to stop.
Still, it looks like from the email that the website creator didn't read the ToS, and consistently consumed significantly more resources than allowed for a few months.
It is pretty visible now. Was it pretty visible before? Was it the same amount when OP signed up? That's what he is arguing, it wasn't a limitation when he started to pay.
They have ALWAYS been very visible. They may have changed just like the cost of the VPS or whatever infrastructure you rent may change. I'm not arguing that serverless platforms have fair pricing—I don't think they do—but I'm arguing that if you subscribe to a platform that bills on usage, it's 100% your fault if you fail to monitor your usage and get insane bills.