There are light-years between what a company thinks their ToS “allow” and what a court would actually determine is allowed. Plenty of ToS clauses in major contracts are unenforceable by law.

In this situation if it were to actually go to court I’d expect the actual bill to get significantly reduced at the very least. But because it’s a completely bullshit charge based on bandwidth usage (which costs them nothing) it won’t go anywhere near that and will just get written off anyway.