TCP session close? Don't reply back the UDP response? Stop scheduling time on the satellite transceiver for that account?

Interesting that you mention UDP, because I'm in the process of adding hard-limits to my service that handles UDP. It's not trivial, but it is possible and while I'm unsympathetic to folks casting shade on AWS for not having it, I decided a while back it was worth adding to my service. My market is experimenters and early stage projects though, which is different than AWS (most revenue from huge users) so I can see why they are more on the "buyer beware" side.