Welcome to the community and thanks for posting. Sorry to hear your new shiny MiFi device isn't working. I understand you're desperate to get this up and running.
SIM cards usually require activation for authentication purposes. If you were sent a new SIM card then I believe the team do have the option of sending it already activated. I'd imagine it would have been included in the leaflet somewhere.
I see this post is from Thursday, how are things looking now?