Too harsh? Do you really believe they never got that information? Emails don't vanish anymore. They either tried to hide their carelessness and blame you for not doing it on time or were just too stupid to do it. I don't think being angry about it is being harsh. Maybe they are not able to do it but that doesn't make it better because they could just ask on time.

Even if I try hard, it's impossible not to laugh. XD