Brookfield Properties Administrative Assistant interview questions

After I applied online at the end of March, I received a phone call to schedule an interview with one of the managers the first week in April. The interview went well and was very laid back, felt more like a conversation. A follow up interview was scheduled with another one of the managers and the Administrative Assistant that following week. The interviews were average. The only negative thing is that although the interviews went fairly well, I never heard back from anyone regarding the position, even after sending them a thank you e-mail. I felt that that was unprofessional coming from a company of their caliber.