From personal experience, I know the internet goes down from time to time, so if you want to ensure your message is rec'd phoning is a good alternative.
Having said that, even with internet interruptions, it rarely takes more than a day or two to get back up and working........your call. Sounds to me like they may not have rec'd your emails.
We've learned to use a back-up for the back-up here - relating to pretty much everything.......it's the good ole DR - hhaha