Don't Know

There is a class I was hoping would be offered in summer online to save me from going to campus on both Monday and Tuesday in Fall. I emailed the grad student liason today to ask if they have made a decision and she told me it would indeed be offered in summer and that I should drop the one for Fall. I go to verify that the course is listed in the system so that I can drop one and sign up for the other. Nope. Not there. Only the undergradaute equivalent. I refuse to drop this class without seeing the other one listed for Summer because I could totally see a situation where I drop the Fall one, the decide not to run the Summer one, I try to resign up for Fall and it's full. No thank you. These thoughts are followed by the following emails:

Me: I don't see this class posted yet in the listings of summer courses, unles I'm overlooking it. Do you know the dates for summer registration, perhaps it will be listed closer to that date?
Her: Don't know.

Umm...ok??? Who might know if not you? It's really unprofessional to just tell me you don't know. You can say you don't know but you'll get back to me, you don't know but here's who would...but not just you don't know. That's incredibly ridiculous.