They work on Mondays. They try to respond within 24 hours on work days or something like that. I understood that to mean that if you submitted your ticket on a Friday afternoon, you should get a response by Monday afternoon or Tuesday morning.
You can login to Pro Support and change the priority of your ticket, or you can email them on [email protected]. @Olivia_Rust commented today that there was some issue with licensing so that could also be it. See her comment at Bought 4 upgrade licenses for version 8 but am still on 7