Maybe they are so back logged they haven't checked emails lately to focus on their current work load? (I remember reading something earlier about the 8+ week waits times?). Although I never had a 2 week cease in communications with Heir. At one point it took them a little over a week to respond to me though.
But that really isn't an excuse for UM Aus since they do not make the CIEMs. UM labs does and they have no difficulty answering my emails in a day or even in a few hours, so why should UM Aus?