I'm curious, personally, what decorum dictates at this point... I know it's probably provocative to issue an ultimatum of a date that the company *needs* to respond by, but at the same time, you also can't just say "get back to me in your own time" as there's no schedule involved there...
Would it be appropriate to say "We're looking for a response by X date, even if it's to say that you're currently consulting with representation to issue an official response"? Would that at least signal that they're paying attention to these new uprisings, without issuing an official response? And then a followup could be to say "Thank you for getting back to us, we'll grant some followup grace period" to give them an *actual* ultimatum date?
Once they acknowledge that they're formulating a response, I would think an official 2-week-or-so date should be sufficient for them to get their ducks in a row as far as issuing an official response, and outside of that, slapping them with the actual suit for failure to attempt to remedy the situation in a timely/good-faith means...