It should be criminal!
Does your client have a support plan with Informatica? The best way is to enter an escalated ticket through that system. We've had good luck with that process.
Sorry to hear that. Does your client have a supprt contract with us? In that case they should be able to open a case via Web 24/7.
Once the registered contact logins to the portal, there is an option @Esupport. Clicking that will take them to the Web case management tool.