@usdiplomat One thing to remember is this: while we may hear the response time, there are also other factors in play. Perhaps the person who needs to coordinate things is gone for a couple days. Perhaps they are researching where/ when to fit you in, and are waiting for answers from other departments.

When I was in a manufacturing company and would be asked the timelines for a product, after confirming with the production manager, I always added a couple of days. The timelines from that production manager was "best case scenario". This way, if there was a glitch, the added days I gave to the customer would save us. Perhaps if you can think of not getting a response like you want, in terms of they are trying for you, it will be easier to take.
Ginger