Oh, so Hertz has gotten wise to... every online platform that exists: Outsourcing all responsibility for their user-hostile bullshit to some vague "system" that cannot be held accountable.
I'm so sorry but the advertised cost has doubled because... Computer says so! No, sir, there's nothing I can do, sir, you see it's the system.
And you can't go anywhere else, because everyone else is doing it (or soon will be) too!